Optically active ester derivatives, preparation process thereof, liquid crystal materials and a light switching element

ABSTRACT

Disclosed are herein optically active ester derivatives represented by the formula (I): ##STR1## (wherein R 1  represents an alkyl group having 3 to 20 carbon atoms; R 2  represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; X represents --COO-- or --OCO--; l represents a number of 1 or 2; k and m each represents a number of 0 or 1; n represents a number of 1 to 6), preparation processes therefor, liquid crystal materials containing such ester derivatives as active ingredient, and a light switching element using said liquid crystal materials as liquid crystal element.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to optically active ester derivatives, processfor producing the same, liquid crystal composition containing saidderivatives as active ingredient and light switching element employingsaid liquid crystal composition.

The optically active ester derivatives are useful as liquid crystalcompounds, especially ones showing excellent responsiveness in videodisplay. Further, the optically active ester derivatives can be workedinto liquid crystal compositions that can be utilized as a liquidcrystal element for producing a light switching element.

When the term "liquid crystal compounds" is used in this specification,it means not only those derivatives which are per se capable of forminga liquid crystal phase but also the derivatives which are useful as acomponent to blended for a liquid crystal even if they per se cannot beobserved as a liquid crystal phase.

2. Description of the Prior Art

Image display devices utilizing liquid crystal are now widely providedfor practical application, and particularly, TN (twisted nematic) typedisplay system is popularly employed for such devices.

This system has many advantages such as small power consumption andsoftness to the eye because of the light-receiving type display panelwhich itself is not luminous, but on the other hand it has the defectthat the response speed in image display is low.

High-speed response is however, especially required in the recent imagedisplays, and many efforts have been made for improving the responsecharacteristics of the liquid crystal compounds. However, theabove-mentioned twisted nematic type display system still can not standcomparison with the luminescent type display systems such aslight-emitting diode, electroluminescence or plasma displays in responsetime.

Efforts have been continued for finding out a new display system whichis capable of high-speed response while making full use of theadvantages of liquid crystal displays which are light-receiving type andlow in power consumption, and one result thereof has been the proposalof a display device utilizing the optical switching phenomenon offerroelectric liquid crystal such as disclosed in Applied PhysicalLetter, 36, 899 (1980).

This system utilizes chiral smectic phases such as chiral smectic Cphase which shows ferroelectricity (hereinafter referred to as "Sc*").It is known that not only the Sc*, but also chiral smectic F, G, H, andI phases show ferroelectricity.

Ferroelectric liquid crystals to be used for actually used ferroelectricliquid crystal display devices are required to have manycharacteristics. However, at present these requirements cannot besatisfied by only one compound and ferroelectric liquid crystalcompositions obtained by mixing some liquid crystal compounds ornon-liquid crystal compounds must be used for satisfying them.

Such ferroelectric liquid crystal compositions may be not only thosewhich comprise only ferroelectric liquid crystal compounds. JapanesePatent Kokai (Laid-open) No. 61-195187 has reported to obtainferroelectric liquid crystal compositions by mixing compound orcomposition which forms non-chiral smectic C, F, G, H, or I phase(hereinafter referred to as "phase such as Sc") as a basic substancewith one or more compounds which forms ferroelectric liquid crystalphase, thereby to make the whole a ferroelectric liquid crystalcomposition. Furthermore, a report has been made to mix a compound orcomposition which forms a phase such as Sc as a basic substance with oneor more compounds which are optically active, but show no ferroelectricliquid crystal phase to make the whole a ferroelectric liquid crystalcomposition. (Mol. Cryst. Liq. Cryst. 89, 827 (1982)).

From the above, it is seen that a ferroelectric liquid crystalcomposition can be produced by mixing a basic substance with one or morecompounds which is optically active irrespective of formingferroelectric liquid crystal phase or not. However, the optically activesubstance is preferably capable of forming liquid crystal phase and evenif it cannot form liquid crystal phase, it is preferably one havingstructure which resembles a liquid crystal compound, so to speak, aquasi-liquid crystal substance. However, there have not yet been foundliquid crystal materials which have spontaneous polarization necessaryfor high speed response and have liquid crystallinity in the lowertemperature region.

Under the circumstances, the present invention provides a ferroelectricliquid crystal material which has sufficient spontaneous polarization,has high speed responsiveness and besides has liquid crystallinity inthe lower temperature region.

SUMMARY OF THE INVENTION

The present invention provides the optically active ester derivativesrepresented by the formula (I): ##STR2## (wherein R₁ represents an alkylgroup having 3 to 20 carbon atoms; R₂ represents an optically activealkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionallysubstituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; Xrepresents --COO-- or --OCO--; l represents a number of 1 or 2; k and meach represents a number of 0 or 1; n represents a number of 1 to 6),preparation processes therefor, liquid crystal compositions containingsuch ester derivatives as active ingredient, and a light switchingelement using said liquid crystal compositions as liquid crystalelement.

DETAILED DESCRIPTION OF THE INVENTION

The optically active ester derivatives represented by the formula (I)according to this invention can be produced by reacting phenolsrepresented by the formula (II): ##STR3## (wherein R₁, Y, l and m havethe meanings given above) with optically active carboxylic acidcompounds represented by the formula (III): ##STR4## (wherein R₂, k andn have the meanings given above and R' represents a hydroxyl group or ahalogen atom), or by reacting carboxylic acid compounds represented bythe formula (IV): ##STR5## (wherein R₁, Y, l and m having the meaningsgiven above and R' represents a hydroxyl group or a halogen atom) withoptically active phenols represented by the formula (V): ##STR6##(wherein R₂, k and n having the meanings given above).

The optically active carboxylic acid compounds (III) containingasymmetric carbon can be produced, for instance,

i) k=0 and n=1 or 2 ##STR7## (in the above reaction formulas, X'represents a halogen atom)

ii) k=0 and n=3, 4, 5, or 6 ##STR8##

iii) k=1 ##STR9## (in the above reaction formulas, Z represents atetrahydropyranyl group, a t-butyldimethylsilyl group, a benzyl group,etc.).

Another process for producing the optically active carboxylic acidcompounds (III) is as follows.

i) k=0 and n=1

It can be produced by hydrolysis of an optically active benzoaterepresented by the formula (IX): ##STR10## (wherein R₂ has the meaninggiven above and R₃ represents a lower alkyl group).

This hydrolysis reaction is carried out in the presence of water andusually in the presence of acids or alkalis.

The acids used here include, for example, inorganic acids such assulfuric acid, phosphoric acid and hydrochloric acid and organic acidssuch as toluene-sulfonic acid and methanesulfonic acid. The alkalisinclude, for example, organic and inorganic bases such as sodiumhydroxide, potassium hydroxide, barium hydroxide, potassium carbonate,and 1,8-diazabicyclo[5,4,0]7-undecene.

Amounts of these acids or alkalis are as follows. The acids are usedpreferably in an amount of 0.02 to 10 mols per 1 mol of the startingcompound (IX) and alkalis are used preferably in an amount of at least 1mol and preferably 5 mols or less per 1 mol of the compound (IX), but,of course, may be used in an amount of more than 5 mols. These arenormally used together with solvents and examples of such solvents areas follows.

Water and aliphatic or aromatic hydrocarbons, ethers, alcohols, ketones,amides, and halogenated hydrocarbons such as methanol, ethanol,propanol, acetone, methyl ethyl ketone, chloroform, dichloromethane,toluene, xylene, hexane, heptane, ethyl ether, tetrahydrofuran, dioxane,dimethylformamide, and N-methylpyrrolidone which are inert to thereaction. These may be used alone or in combination of two or more.Amount thereof is not critical.

Reaction temperature is usually -30° C.-120° C., preferably -20° C.-100°C.

Reaction time is not critical. After completion of the reaction, theoptically active carboxylic acid compounds (III) are obtained in highyields by ordinary separating means such as extraction, separation ofliquid phase, concentration and recrystallization and, if necessary, theproducts may be purified by column chromatography, etc.

The above hydrolysis reaction is more preferably carried out in thepresence of an alkali because both the product carboxylic acid compound(III) and the starting compound (IX) have an ether linkage.

The optically active benzoates represented by the formula (IX) can beproduced by one of the following two processes.

The first process comprises reacting a benzyl alcohol represented by theformula (X): ##STR11## (wherein R₃ has the meaning given above) with anoptically active alkylating agent represented by the formula (XI):

    R.sub.2 --X.sub.1                                          (XI)

(wherein R₂ has the meaning given above and X₁ represents a halogen atomor --O--OS₂ R"' in which R"' represents a lower alkyl group or a phenylgroup which may be substituted with a lower alkyl group).

The above alkylation reaction is carried out usually in the presence ofa basic substance, which includes, for example, alkali metal hydridessuch as sodium hydride and potassium hydride, alkali metals such aslithium, sodium and potassium, alkali metal alcoholates such as sodiumethylate and sodium methylate, alkali metal carbonates such as sodiumcarbonate and potassium carbonate, and butyl lithium.

The basic substance must be used in an amount of at least 1 equivalentto the benzyl alcohol (X) and preferably 3 equivalents or less thoughthere is no special upper limit.

The starting compound benzyl alcohol (X) and the optically activealkylating agent (XI) may be used in various amounts depending ondifficulty in availability.

That is, in general the benzyl alcohol (X) is inexpensive and easier inavailability than the optically active alkylating agent (XI). Therefore,it is preferred to use the benzyl alcohol in excess amount over theamount of the optically active alkylating agent (XI) and amount of thebenzyl alcohol (X) is 1-5 equivalents, especially preferably 1-3equivalents to the optically active alkylating agent (XI).

However, in case the alkylating agent (XI) is cheaper than the benzylalcohol (X), it is preferred to use the alkylating agent in an excessamount over the amount of the benzyl alcohol.

The alkylating agent used in the reaction includes, for example, halidessuch as chlorides, bromides and iodides or sulfuric esters (such asmethanesulfonates, ethanesulfonates, benzenesulfonates andtoluenesulfonates) which have an optically active alkyl group oralkoxyalkyl group having 3 to 15 carbon atoms optionally substitutedwith halogen atom as mentioned later.

The optically active alkylating agents (XI) can be produced byhalogenation or esterification with sulfonic acid of optically activealcohols (XII) which will be referred to hereafter.

In case of substituent R₂ in the formula (XI) being an optically activealkyl group containing bromine or iodine atom, in general, sulfonic acidesters are favorably used as the alkylating agent from the point ofyield.

On the other hand, in case the substituent R₂ being an optically activealkyl group containing fluorine or chlorine atom, bromides or iodides asalkylating agent can be used without any problems owing to difference inreactivity.

As reaction solvents, there may be used those which are inert to thereaction, for example, aliphatic or aromatic hydrocarbons, ethers, andhalogenated hydrocarbons such as tetrahydrofuran, ethyl ether, acetone,methyl ethyl ketone, toluene, benzene, chlorobenzene, dimethylformamide,and hexane. These are used alone or in combination and amount thereof isnot critical.

It is also possible to use polar solvents such as dimethylsulfoxide,hexamethylphosphoryl amide, and N-methylpyrrolidone.

Reaction temperature is usually -50° C. to 120° C., preferably -30° C.to 100° C.

The second process comprises reacting an optically active alcoholrepresented by the formula (XII):

    R.sub.2 --OH                                               (XII)

(wherein R₂ has the meaning given above) with benzoic acid esterderivative represented by the formula (XIII): ##STR12## (wherein R₃ andX₁ have the meanings given above).

The above benzoic acid ester derivative (XIII) can be produced byhalogenation of benzyl alcohol represented by the formula (X) withphosphorus tribromide or esterification of the benzyl alcohol (X) withmethanesulfonyl chloride or toluenesulfonyl chloride.

With reference to the optically active alcohols (XII), commerciallyavailable products can be used for some of them, but, if necessary, theycan be easily obtained by asymmetric reduction of corresponding ketoneswith asymmetric metal catalyst, microorganism, or enzyme.

Further, some of them can be derived from the following optically activeamino acids and optically active oxyacids which occur in nature or theobtained by resolution.

Valine, leucine, isoleucine, phenylalanine, threonine, allothreonine,homoserine, alloisoleucine, tert-leucine, 2-aminobutyric acid,norvaline, norleucine, ornithine, lysine, hydroxylsine, phenylglycine,aspartic acid, glutamic acid, mandelic acid, tropic acid,3-hydroxybutyric acid, malic acid, tartaric acid, isopropylmalic acid,etc.

The reaction conditions for alkylation in the first process explainedabove as they are can be employed for the reaction of the opticallyactive alcohol (XII) with the benzoic acid ester derivative (XIII).

Regarding the amounts of the optically active alcohol (XII) and thebenzoic acid ester derivative (XIII), it is generally, preferred to usethe derivative (XIII) in an excess amount over the amount the alcohol(XII) because the former is cheaper and easier in availability than thelatter. Amount of the derivative (XIII) is 1 to 5 equivalents,especially preferably 1-3 equivalents to the alcohol (XII).

The substituent R₂ of the optically active alcohol (XII) includesoptically active alkyl or alkoxyalkyl group exemplified later.

ii) k=0 and n=2, 3, 4, 5 or 6

The optically active carboxylic acid compounds (III) can be produced byoxidizing an optically active acetophenone represented by the formula(VI): ##STR13## (wherein R₂ has the meaning given above) with anoxidizing agent.

As the oxidizing agent used in the above reaction, there may be used anyof those which oxidize an acetyl group to produce a carboxylic acid andthere is no special limitation. Such oxidizing agents include, forexample, potassium bichromate, sodium bichromate, potassiumpermanganate, sodium permanganate, potassium hydrochlorite, sodiumhypochlorite, potassium hypobromite, and sodium hypobromite.

Amount of the oxidizing agent is at least 1 equivalent to the opticallyactive acetophenone (VI) and preferably is 10 equivalents or less thoughthere is no special limitation in upper limit.

Solvents which are normally inert to oxidation reaction are used forthis reaction and examples of such solvents are water, dioxane,tetrahydrofuran and N-methylpyrrolidone.

Reaction temperature is usually -20° C. to 130° C., preferably -10° C.to 100° C.

After completion of the reaction, the optically active carboxylic acidcompound (III) can be obtained in high yields by usual separating meanssuch as filtration, acidification, extraction, separation of liquidphase, and concentration and, if necessary, this etc.

The optically active acetophenone (VI) can be produced by reacting analkanol compound represented by the formula (XV): ##STR14## (wherein n'represents a number of 2 to 6) with the above-mentioned optically activealkylating agent represented by the formula (XI).

Conditions for this reaction are similar to those for the aforementionedreaction of benzyl alcohol (X) and alkylating agent (XI).

The alkanol compound represented by the formula (XV) can be produced byhydrolysis of a lower alkanoic acid ester represented by the formula(XVI): ##STR15## (wherein R₄ represents a lower alkyl group; n' has themeaning given above).

The conditions for the aforementioned hydrolysis of the optically activebenzoic acid ester (IX) can be applied to this reaction.

The lower alkanoic acid ester represented by the formula (XVI) can beproduced by acetylation of a benzene compound represented by the formula(XVII): ##STR16## (wherein R₄ and n' have the meaning given above).

The ordinary Friedel-Crafts reaction is applied to this acetylation.

Acetic acid derivatives used for the acetylation include, for example,acetic acid, acetyl chloride and acetyl bromide. Amount of the aceticacid derivative used is at least 1 mol per 1 mol of the benzene compound(XVII) and preferably is 3 mols or less per 1 mol of the benzenecompound. Catalysts used for the acetylation are those which are usedfor ordinary Friedel-Crafts reaction and examples thereof are aluminumchloride, aluminum bromide, zinc chloride, zinc bromide, titaniumtetrachloride, polyphosphoric acid and boron trifluoride. These are usedin an amount of 0.3 to 3 mols per 1 mol of benzene compound (XVII).

Reaction temperature is usually -30° C. to 150° C., preferably -10° C.to 100° C.

Reaction time is not critical.

From the thus obtained reaction mixture, the lower alkanoic acid esterrepresented by the formula (XVI) can be obtained in high yields byoperations such as separation of liquid phase, concentration,distillation and recrystallization.

The above-mentioned optically active carboxylic acid compound (III)include, for example, 4-(alkoxymethyl)benzoic acid,4-(2-alkoxyethyl)benzoic acid, 4-(3-alkoxypropyl)benzoic acid,4-(4-alkoxybutyl)benzoic acid, 4-(5-alkoxypentyl)benzoic acid,4-(6-alkoxyhexyl)benzoic acid, 4-(alkoxyalkoxymethyl)benzoic acid,4-(2-alkoxyalkoxyethyl)benzoic acid, 4-(alkanoyloxymethyl)benzoic acid,4-(2-alkanoyloxyethyl)benzoic acid, 4-alkoxyalkanoyloxymethyl)benzoicacid, 4-(2-alkoxyalkanoyloxyethyl)benzoic acid,4-(3-alkoxyalkoxypropyl)benzoic acid, 4-(4-alkoxyalkoxybutyl)benzoicacid, 4-(5-alkoxyalkoxypentyl)benzoic acid,4-(6-alkoxyalkoxyhexyl)benzoic acid, 4-(3-alkanoyloxypropyl)benzoicacid, 4-(4-alkanoyloxybutyl)benzoic acid, 4-(5-alkanoyloxypentyl)benzoicacid, 4-(6-alkanoyloxyhexyl)benzoic acid,4-(3-alkoxyalkanoyloxypropyl)benzoic acid,4-(4-alkoxyalkanoyloxybutyl)benzoic acid,4-(5-alkoxyalkanoyloxypentyl)benzoic acid, and4-(6-alkoxyalkanoyloxyhexyl)benzoic acid.

The above alkyl, alkoxyalkoxy, alkanoyloxy or alkoxyalkanoyloxycorresponds to ##STR17## in the formula (III) and the substituent R₂ isan optically active alkyl or alkoxyalkyl group having an asymmetriccarbon and having 3.to 15 carbon atoms which may be substituted with ahalogen atom.

In case of k=0, specific examples of the above alkyl group andalkoxyalkyl group are 1-methylpropyl, 1-methylbutyl, 2-methylbutyl,1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl,2,3,3-trimethylbutyl, 1,2,2-trimethylbutyl, 2-methylpentyl,1-methylpentyl, 3-methylpentyl, 1,2-dimethylpentyl, 2,3-dimethylpentyl,2,4-dimethylpentyl, 1,2,2,3-tetramethylpentyl,2,3,3,4-tetramethylpentyl, 1-methylhexyl, 2-methylhexyl, 3-methylhexyl,4-methylhexyl, 1,2-dimethylhexyl, 1,4-dimethylhexyl, 2,5-dimethylhexyl,1-methylheptyl, 2-methylheptyl, 5-methylheptyl, 1,3-dimethylheptyl,2-methyloctyl, 6-methyloctyl, 1,4-dimethyloctyl, 1-methylnonyl,3-methylnonyl, 5-methylnonyl, 7-methylnonyl, 1,2-dimethylnonyl,1-methyldecyl, 3-methyldecyl, 7-methyldecyl, 8-methyldecyl,1-methylundecyl, 9-methylundecyl, 1-methyldodecyl, 10-methyldodecyl,methoxyethyl, methoxypropyl, methoxybutyl, methoxypentyl, methoxyhexyl,methoxyheptyl, methoxyoctyl, methoxynonyl, methoxydecyl, methoxyethyl,ethoxypropyl, ethoxybutyl, ethoxypentyl, ethoxyhexyl, ethoxyheptyl,ethoxyoctyl, ethoxynonyl, ethoxydecyl, propoxyethyl, propoxypropyl,propoxybutyl, propoxypentyl, propoxyhexyl, propoxyheptyl, propoxyoctyl,propoxynonyl, propoxydecyl, butoxyethyl,, butoxypropyl, butoxybutyl,butoxypentyl, butoxyhexyl, butoxyheptyl, butoxyoctyl, butoxynonyl,butoxydecyl, pentyloxyethyl, pentyloxypropyl, pentyloxybutyl,pentyloxypentyl, pentyloxyhexyl, pentyloxyoctyl, pentyloxydecyl,hexyloxyethyl, hexyloxypropyl, hexyloxybutyl, hexyloxypentyl,hexyloxyhexyl, hexyloxyoctyl, heptyloxyethyl, heptyloxypropyl,heptyloxybutyl, heptyloxypentyl, octyloxyethyl, octyloxypropyl,decyloxyethyl, decyloxypropyl, 2-trihalomethylpentyl,2-trihalomethylhexyl, 2-trihalomethylheptyl, 2-halopropyl,3-halo-2-methylpropyl, 2,3-dihalopropyl, 2-halobutyl, 3-halobutyl,2,3-dihalobutyl, 2,4-dihalobutyl, 3,4-dihalobutyl, 2-halo-3-methylbutyl,2-halo-3,3-dimethylbutyl, 2-halopentyl, 3-halopentyl, 4-halopentyl,2,4-dihalopentyl, 2,5-dihalopentyl, 2-halo-3-methylpentyl,2-halo-4-methylpentyl, 2-halo-3-monohalomethyl-4-methylpentyl,2-halohexyl, 3-halohexyl, 4-halohexyl, 5-halohexyl, 2-haloheptyl and2-halooctyl (wherein "halo" indicates fluorine, chlorine, bromine oriodine).

In addition to the above substituents, when k is 1, there are recited1-halopropyl, 1-halobutyl, 1-halopentyl, 1-halohexyl, 1-haloheptyl,1-halooctyl, 1-halo-2-methylpropyl, 1-halo-2-methylbutyl,1-halo-2-methylpentyl, 1-halo-2-methylhexyl, 1-halo-2-methylheptyl,1-halo-2-methyloctyl and the like.

The optically active phenols (V) containing asymmetric carbon can beproduced, for instance,

i) k=0 ##STR18##

ii) k=1 ##STR19##

As such optically active phenols (V), mention may be made of, forexample, 4-(alkoxymethyl)phenol, 4-(2-alkoxyethyl)phenol,4-(3-alkoxypropyl)phenol, 4-(4-alkoxybutyl)phenol,4-(5-alkoxypentyl)phenol, 4-(6-alkoxyhexyl)phenol,4-(alkoxyalkoxymethyl)phenol, 4-(2-alkoxyalkoxyethyl)phenol,4-(alkanoyloxymethyl)phenol, 4-(2-alkanoyloxyethyl)phenol,4-(alkoxyalkanoyloxymethyl)phenol, 4-(2-alkoxyalkanoyloxyethyl)phenol,4-(3-alkoxyalkoxypropyl)phenol, 4-(4-alkoxyalkoxybutyl)phenol,4-(5-alkoxyalkoxypentyl)phenol, 4-(6-alkoxyalkoxyhexyl)phenol,4-(3-alkanoyloxypropyl)phenol, 4-(4-alkanoyloxybutyl)phenol,4-(5-alkanoyloxypentyl)phenol, 4-(6-alkanoyloxyhexyl)phenol,4-(3-alkoxyalkanoyloxypropyl)phenol, 4-(4-alkoxyalkanoyloxybutyl)phenol,4-(5-alkoxyalkanoyloxypentyl)phenol, and4-(6-alkoxyalkanoyloxyhexyl)phenol. These may also be used as metalphenolate or tosylate.

The above alkoxy, alkoxyalkoxy, alkanoyloxy or alkoxyalkanoyloxycorresponds to ##STR20## in the formula (V) and the substituent R₂includes those which are exemplified above as R₂ in the formula (III).

Production of the optically active phenols (V) will be explained indetail.

i) k=0

They can be produced by hydrolysis of an optically activeacetyloxybenzene compound represented by the formula (VIII): ##STR21##(wherein R₂ and n have the meanings given above).

The same conditions as used for hydrolysis of the optically activebenzoic acid esters (IX) mentioned above can be applied to thisreaction.

The optically active acetyloxybenzene compounds represented by theformula (VIII) can be produced by Baeyer-Villiger oxidation of theabove-mentioned optically active acetophenone represented by the formula(VI) with a peracid.

The peracid includes, for example, peracetic acid, performic acid,m-chloroperbenzoic acid, and perbenzoic acid. These peracids can beproduced, for example, from a corresponding acid and hydrogen peroxide.The Bayer-Villiger oxidation can also be conducted while a peracid isproduced in the reaction system.

Amount of the peracid is ordinarily at least 1 equivalent to theoptically active acetophenone represented by the formula (VI) and ispreferably 5 equivalents or less though there is no special limitationin upper limit.

As solvents used in this reaction, normally those which are inert to theoxidation reaction are used and examples thereof are water and ethers,ketones, esters, halogenated hydrocarbons and aromatic or aliphatichydrocarbons such as dioxane, tetrahydrofuran, N-methylpyrrolidone,di-n-butyl ether, ether, ethyl acetate, n-propyl acetate,dichloromethane, dichloroethane, chloroform, chlorobenzene, benzene,toluene, xylene, hexane, and cyclohexane. These may be used singly or incombination.

Reaction temperature is usually -10° C. to 100° C., preferably 0° C. to90° C.

ii) k=1

The optically active phenols can be produced by carrying out reaction ofan optically active benzyloxyphenyl compound represented by the formula(VII): ##STR22## (wherein R₂ and n have the meanings given above) in asolvent in the presence of a hydrogenation catalyst and hydrogen gas.

As the hydrogenation catalyst, mentioned may be made of, for example,platinum based catalysts such as PtO₂ and Pt-C, palladium basedcatalysts such as Pd-C, Pd-BaSO₄, and palladium black, rhodium basedcatalysts such as Rh-C and Rh-Al₂ O₃, ruthenium based catalysts such asRuO₂ and Ru-C and nickel based catalysts such as Raney nickel. Preferredare palladium based catalysts.

The hydrogenation catalyst is used generally in an amount of 0.01 to100% by weight, preferably 0.1 to 50% by weight of the optically activebenzyloxyphenyl compound represented by the formula (VII).

As examples of the solvent, mention may be made of alcohols such asmethanol and ethanol, ethers such as dioxane and tetrahydrofuran,aromatic hydrocarbons such as benzene and toluene, aliphatichydrocarbons such as n-hexane and cyclohexane, esters such as ethylacetate, amides such as dimethylformamide, fatty acids such as aceticacid, and water. These may be used singly or in combination. These maybe used singly or in combination. Hydrogen pressure is usually 1 to 200atm.

The reaction is carried out usually at 0° to 200° C., more preferably20° to 180° C. Reaction time varies depending on kind of hydrogenationcatalyst, reaction temperature and hydrogen pressure and is notcritical, but end point of the reaction is normally determined bydisappearance of the benzyloxyphenyl compound (VII) from the reactionsystem or termination of hydrogen absorption.

Separation of the optically active phenol represented by the formula (V)from the reaction mixture is carried out by usual aftertreatment such asfiltration, concentration, recrystallization, distillation and columnchromatography.

The optically active benzyloxyphenyl compound represented by the formula(VII) can be produced by reacting a phenylalkyl alcohol represented bythe formula (XVIII): ##STR23## (wherein n has the meaning given above)with an optically active carboxylic acid represented by the formula(XIX):

    R.sub.2 COOH                                               (XIX)

(wherein R₂ represents an optically active alkyl or alkoxyalkyl groupwhich may be substituted with a halogen atom and which has 3 to 15carbon atoms) or a derivative thereof in the presence of a catalyst or acondensing agent.

Examples of the phenylalkyl alcohols (XVIII) are as follows:

1-benzyloxy-4-hydroxymethylbenzene,

1-bebzyloxy-4-(2-hydroxyethyl)benzene,

1-benzyloxy-4-(3-hydroxypropyl)benzene,

1-benzyloxy-4-(4-hydroxybutyl)benzene,

1-benzyloxy-4-(5-hydroxypentyl)benzene, and

1-benzyloxy-4-(6-hydroxyhexyl)benzene.

These phenylalkyl alcohols (XVIII) can be produced by reacting acorresponding 4-hydroxyalkylphenol with benzyl chloride, for example, inthe presence of sodium hydride.

In the reaction of the phenylalkyl alcohol (XVIII) with the opticallyactive aliphatic carboxylic acid or a derivative thereof, a freecarboxylic acid, acid anhydride thereof or an acid halide such as acidchloride or acid bromide is used.

Some of the optically active aliphatic carboxylic acids (XIX) can beobtained by oxidation of corresponding alcohols or reductive deaminationof amino acid and some of others can be derived from the followingoptically active amino acids or optically active oxyacids which occur innature or are obtained by resolution.

Alanine, valine, leucine, isoleucine, phenylalanine, serine, threonine,allothreonine, homoserine, alloisoleucine, tert-leucine, 2-aminobutyricacid, norvaline, norleucine, ornithine, lysine, hydroxylysine,phenylglycine, trifluoroalanine, aspartic acid, glutamic acid, lacticacid, mandelic acid, tropic acid, 3-hydroxybutyric acid, malic acid,tartaric acid and isopropylmalic acid.

Conditions for the reaction of phenylalkyl alcohols (XVIII) with theoptically active aliphatic acids or derivatives thereof are similar tothose for the reaction of carboxylic acid compounds (IV) and theoptically active phenols (V).

The phenols (II) and carboxylic acid compounds (IV) used as anotherstarting material in said reactions are mostly the known compounds andcan be produced according to the methods disclosed in the literature.

Examples of such phenols (II) and carboxylic acid compounds (IV) are asfollows: 4-alkoxyphenol, 4-alkylphenol, 4'-alkoxy-4-hydroxybiphenyl,4'-alkyl-4-hydroxybiphenyl, 4-alkoxycarbonylphenol,4-alkylcarbonyloxyphenol, 4'-alkoxycarbonyl-4-hydroxybiphenyl,4'-alkylcarbonyloxy-4-hydroxybiphenyl, 4-alkoxybenzoic acid,4-alkylbenzoic acid, 4'-alkoxy-4-biphenylcarboxylic acid,4'-alkyl-4-biphenylcarboxylic acid, 4-alkoxycarbonylbenzoic acid,4-alkylcarbonyloxybenzoic acid, 4'-alkoxycarbonyl-4-biphenylcarboxylicacid, and 4'-alkylcarbonyloxy-4-biphenylcarboxylic acid.

The above alkyl and alkoxy have a straight chain alkyl group having 3 to20 carbon atoms. Typical examples of the alkyl groups are as follows.

Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,octadecyl, nonadecyl and eicosyl.

The phenols (II) can be reacted with the optically active carboxylicacids (III) as metal phenolates.

Furthermore, carboxylic acids (IV) can also be utilized as acid halides,namely, acid chloride, acid bromide, etc.

An ordinary esterification method can be applied for the reaction ofoptically active phenols (V) and carboxylic acid compounds (IV) or thereaction of optically active carboxylic acids (III) and phenols (II),and such reaction can be carried out in the presence or absence of asolvent by using a catalyst.

In case of using a solvent in these reactions, such solvent is selectedfrom those which are inert to the reaction, such as aliphatic oraromatic hydrocarbons, ethers, halogenated hydrocarbons and the like,the typical examples thereof being tetrahydrofuran, ethyl ether,acetone, methyl ethyl ketone, toluene, benzene, chlorobenzene,dichloromethane, dichloroethane, chloroform, carbon tetrachloride,dimethylformamide, hexane and the like. These solvents may be usedeither singly or in combination. No specific limitations are imposed onthe amount of such solvent(s) used.

Since the optically active phenols (V) and the optically activecarboxylic acids (III) used in the reaction are expensive, it isadvisable to use the other starting material, viz. carboxylic acidcompounds (IV) or phenols (II), in an excess amount, usually 1 to 4equivalents, preferably 1 to 2 equivalents to the optically activephenols (V) or optically active carboxylic acids (III).

As the catalyst, there can be used organic or inorganic basic materialssuch as dimethylaminopyridine, triethylamine, tri-n-butylamine,pyridine, picoline, collidine, imidazole, sodium carbonate, sodiummethylate, potassium hydrogencarbonate and the like.

Organic or inorganic acids such as toluene-sulfonic acid,methanesulfonic acid, sulfuric acid, etc., are also usable as catalyst.

It is also possible to use a condensing reagent in the case ofdehydration for the free carboxylic acids and phenols.

As the condensing reagent, there can be used organic materials such asN,N'-dicyclohexyl carbodiimide,N-cyclohexyl-N'-(4-diethylamino)-cyclohexyl carbodiimide, carbodiimide,imidazoylimidazole and the like.

If necessary there can be used organic amines such as4-pyrollidinopyridine, pyridine, triethylamine and the like.

The amount of a condensing reagent is usually 1 to 1.2 equivalents t thecarboxylic acid.

The amount of the organic amine is usually 0.01 to 0.2 equivalent to acondensing reagent.

The amount of the catalyst to be used is not specified as it variesdepending on the type of the starting materials used, their combinationwith the catalyst used and other factors, but in case of using an acidhalide as a starting material, a basic material is used as catalyst inan amount not less than one equivalent to said acid halide.

The reaction temperature is usually -30° to 100° C. The reaction time isnot subject to any specific limitations.

After the reaction has been completed, the reaction product is subjectedto the ordinary separating means such as extraction, separation ofliquid phase, concentration, etc., to isolate the objective opticallyactive ester derivatives of the formula (I). If necessary, the productmay be purified by column chromatography, recrystallization or othermeans.

The optically active ester derivative to be thus obtained are actuallyexemplified as follows:

In the following examples, "(C₃₋₁₅)" and "(C₃₋₂₀)" mean "having 3-15carbon atoms" and "having 3-20 carbon atoms", respectively.

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylylester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-alkyl(C₃₋₂₀)carbonyloxy]phenylester,

4-[2-alkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)carbonyloxy]phenylester,

4-[alkyl(C₃₋₁₅)oxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[alkyl(C₃₋₁₅)oxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[alkyl(C₃₋₁₅)oxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylylester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid 4'-[alkyl )oxy]biphenylyl ester,

4-[5-alkyl )oxypentyl]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylylester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]diphenylylester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxyliate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl 4-[alkyl(C₃₋₂₀ (]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl 4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl 4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl 4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl 4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid 4-[alkyl oxycarbonyl]phenylester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenyl ester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl 4-[alkyl(C₃₋₂₀)oxyphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl 4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl 4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[2-alkyl )oxyethyl]phenyl 4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarbxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarbxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)carboxyloxy]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[alkylalkyl(C₃₋₁₅)oxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid4-alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]benzoic acid 4'-[alkylC₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)carbonxyoxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[alkyl(C₃₋₂₀)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C3020)oxy]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[-alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4-alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]phenylester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[3-alkoxyalkyl(C₃₋₁₅)]benzoic acid 4'-[alkyl(C₃₋₂₀)oxy]biphenylylester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid 4'-alkyl(C₃₋₂₀)]biphenylylester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid 4'-[alkyl(C₃₋₂₀)]biphenylylester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]bebzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)oxy]phenylester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid 4'-[alkyl(C₃₋₂₀)phenylester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)]phenylester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl)benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)carbobyloxypropylbenzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[6-alkyl )carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonylphenyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[4-alkyl C₃₋₁₅)carbonyloxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxy]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)phenyl ester, -p04-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybytyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxyphentyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)oxy]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylyl ester,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl 4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxymethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)oxyethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[5-alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[alkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[2-alkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxy]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)oxy]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)carbonyloxymethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[2-alkoxyalkyl(C₃₋₁₅)carbonyloxyethyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

1 4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4'-alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxyphenyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)oxypropyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonylbiphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C3020)carbonyloxy]phenyl ester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[alkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[4-alkyl(C₃₋₁₅)carbonyloxybytyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybytyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

5 4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[3-alkoxyalkyl(C₃₋₁₅)carbonyloxypropyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[4-alkoxyalkyl(C₃₋₁₅)carbonyloxybutyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[5-alkoxyalkyl(C₃₋₁₅)carbonyloxypentyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[6-alkoxyalkyl(C₃₋₁₅)carbonyloxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)oxycarbonyl]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl4'-alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)oxycarbonyl]biphenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid4-[-alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[6- )oxyhexyl]benzoic acid 4-[alkyl(C₃₋₂₀)carbonyloxy]phenyl ester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[4-alkyl(C₃₋₁₅)oxybutyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[5-alkyl(C₃₋₁₅)oxypentyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenyl ester,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]benzoic acid4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylyl ester,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[4-alkyl(C₃₋₁₅)oxybutyl]phenyl4-alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[6-alkyl(C₃₋₂₀)oxyhexyl]phenyl4-[alkyl(C₃₋₂₀)carbonyloxy]phenylcarboxylate,

4-[3-alkyl(C₃₋₁₅)oxypropyl]phenyl4'-alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[alkyl(C₃₋₁₅)oxybutyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[5-alkyl(C₃₋₁₅)oxypentyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate,

4-[6-alkyl(C₃₋₁₅)oxyhexyl]phenyl4'-[alkyl(C₃₋₂₀)carbonyloxy]biphenylcarboxylate.

In the above examples, the alkyl or the alkoxyalkyl (of 3 to 15 carbonatoms or 3 to 20 carbon atoms) is as exemplified hereinbefore.

Optically active ester derivatives represented by the formula (I) (X is--OCO-- or --COO--) are obtained by the two processes explained above.When these derivatives are used as constituting elements of liquidcrystal, especially as constituting elements of ferroelectric liquidcrystal and when practical optical stability is taken intoconsideration, substituent R₂ in the formula (I) is preferably an alkylgroup containing no halogen atom and furthermore, mention may be made ofthe compounds of X=--COO-- and n=3 or more as those which exhibit morepreferred properties in practical use.

Furthermore, in order to exhibit high-speed responsiveness which is acharacteristic of ferroelectric liquid crystal, liquid crystallinecompounds of low viscosity coefficint are desired and in case of thecompounds represented by the formula (I), those of l=1 are especiallypreferred. Compounds of l=2 are wide in temperature range at which Sc*phase is formed and Sc* phase of liquid crystal composition can bewidened by using these compounds as one component of liquid crystalcomposition.

The liquid crystal composition of the present invention contains atleast one optically active compound represented by the formula (I) as acomponent. In this case, it is preferred to use the optically activeester derivative represented by the formula (I) in an amount of 0.1 to99.9% by weight, especially preferably 1 to 99% by weight of theresulting liquid crystal composition.

Such liquid crystal composition can be effectively utilized as liquidcrystal elements, especially light switching element and in this case,the liquid crystal composition can be used according to conventionalmethods as they are and the methods of use are not critical.

Thus, according to the present invention, the novel optically activeester derivatives represented by the formula (I) can be easily obtainedin high yields and besides these derivatives have very excellentproperties as liquid crystal compounds and can be effectively utilizedas liquid crystal elements.

Preparation Example 1 (Starting materials)

In a four-necked flask equipped with a thermometer and a stirrer werecharged 4.85 g (20 mmols) of 1-benzyloxy-4-(3-hydroxypropyl)benzene,2.45 g (24 mmoles) of 25-methylbutanoic acid and 50 ml ofdichloromethane and to the mixture were further added 4.95 g (24 mmols)of N,N'-dicyclohexylcarbodiimide and 20 mg of 4-pyrrolidinopyridine,followed by stirring at room temperature for 24 hours.

After completion of the reaction, the reaction mixture was filtered andthe resulting filtrate was washed with 5% acetic acid, water, 5% aqueoussodium bicarbonate solution and saturated aqueous sodium chloridesolution in succession, dried over anhydrous magnesium sulfate and thenconcentrated under reduced pressure. The resulting residue was silicagel column chromatographed (eluent: toluene/ethyl acetate=40/1) toobtain 5.55 g of 1-benzoyl-4-(3-(2S-methylbutanoyloxy)propyl)benzene(VII-1) (yield 85%, [α]_(D) ²⁰ =+7.6° (c=1, CHCl₃), n_(D) ²⁰ =1.5331)

3.26 g (10 mmols) of the obtained (VII-1) was dissolved in 80 ml ofethanol and 0.3 g of 10% Pd/C was added to the solution, followed byvigorous stirring for 12 hours under a hydrogen pressure of 1 to 1.2atm.

After completion of the reaction, Pd/C was filtered off and theresulting filtrate was concentrated under reduced pressure. Theresulting residue was silica gel column chromatographed (eluent:toluene/ethyl acetate=10/1) to obtain 2.24 g (yield 95%) of4-(3-25-methylbutanoyloxy)propyl)phenol (V-1). [α]_(D) ²⁰ =+32.3° (c=1,CHCl₃), n_(D) ²⁰ =1.5058.

Preparation Examples 2-5 (starting materials)

Reaction, aftertreatment and purification were carried out in the samemanner as in Preparation Example 1 except that optically activealiphatic carboxylic acids (XIX) as shown in Table (i) were used inplace of 2S-methylbutanoic acid. The results are shown in Table (i).

                                      TABLE (i)                                   __________________________________________________________________________         Optically active                                                                           Optically active benzyloxy                                                                    Optically active                            Prepa-                                                                             aliphatic carboxylic                                                                       phenyl compound (VII)                                                                         phenols (V)                                 ration                                                                             acid (XIX)           Yield and        Yield and                          Example                                                                            Name   Amount                                                                              Name    properties                                                                            Name     properties                         __________________________________________________________________________    2    4S-methyl-                                                                           3.12 g                                                                              1-benzoyl-4-(3-                                                                       5.88 g (83%)                                                                          4-(3-(4S-methyl-                                                                       2.56 g (97%)                            hexanoic                                                                             (24 mmol)                                                                           (4S-methyl-                                                                           [α].sub.D.sup.20 +6.2°                                                   hexanoyl)-                                                                             [α].sub.D.sup.20                                                        +22.3°                           acid         hexanoyl)-                                                                            (c = 1, CHCl.sub.3)                                                                   propyl)- (c = 1, CHCl.sub.3)                                  propyl)benzene                                                                        n.sub.D.sup.20 1.5248                                                                 phenole (V-2)                                                                          n.sub.D.sup.20 1.5034                                (VII-2)                                                     3    2S-propoxy-                                                                          3.17 g                                                                              1-benzyloxy-4-                                                                        6.27 g (88%)                                                                          4-(3-(2S-propoxy-                                                                      2.56 g (96%)                            propionic                                                                            (24 mmol)                                                                           (3-(2S-propoxy-                                                                       [α].sub.D.sup.20 +5.9°                                                   propanoyl)-                                                                            [α].sub.D.sup.20                                                        +18.7°                           acid         propanoyl)-                                                                           (c = 1, CHCl.sub.3)                                                                   propyl)- (c = 1, CHCl.sub.3)                                  propyl)benzene                                                                        n.sub.D.sup.20 1.5260                                                                 phenole (V-3)                                                                          n.sub.D.sup.20 1.5046                                (VII-3)                                                     4    2S-octyloxy-                                                                         4.86 g                                                                              1-benzyloxy-4-                                                                        7.00 g (82%)                                                                          4-(3-(2S-octyloxy-                                                                     3.16 g (94%)                            propionic                                                                            (24 mmol)                                                                           (3-(2S-octyloxy-                                                                      [α].sub.D.sup.20 +4.3°                                                   propanoyl)-                                                                            [α].sub.D.sup.20                                                        +11.8°                           acid         propanoyl)-                                                                           (c = 1, CHCl.sub.3)                                                                   propyl)- (c = 1, CHCl.sub.3)                                  propyl)benzene                                                                        n.sub.D.sup.20 1.5204                                                                 phenole (V-4)                                                                          n.sub.D.sup.20 1.5018                                (VII-4)                                                     5    2S-chloro-                                                                           3.61 g                                                                              1-benzyloxy-4-                                                                        6.00 g (80%)                                                                          4-(3-(2S-chloro-                                                                       3.62 g (92%)                            3S-methyl-                                                                           (24 mmol)                                                                           (3-(2S-chloro-                                                                        [α].sub.D.sup.20 -3.8°                                                   3S-methyl-                                                                             [α].sub.D.sup.20                                                        -7.9°                            pentanoic    3S-methyl-                                                                            (c = 1, CHCl.sub.3)                                                                   pentanoyl)                                                                             (c = 1, CHCl.sub.3)                     acid         pentanoyl)-                                                                           n.sub.D.sup.20 1.5372                                                                 propyl)phenol                                                                          n.sub.D.sup.20 1.5188                                propyl)benzene                                                                (VII-5)                                                     __________________________________________________________________________

Preparation Example 6 (starting materials)

Reaction, aftertreatment and purification were carried out in the samemanner as in Preparation Example 1 except that1-benzyloxy-4-(2-hydroxyethyl)benzene was used in place of1-benzyloxy-4-(3-hydroxypropyl)benzene to obtain 5.50 g (yield 88%) of1-benzyloxy-4-(2-(2S-methylbutanoyl)ethyl)benzene (VII-6).

[α]_(D) ²⁰ =+8.2° (c=1, CHCl₃),

n_(D) ²⁰ =1.5340.

Further, reaction, aftertreatment and purification were carried out inthe same manner as in Preparation Example 1 except that the aboveobtained (VII-6) was used in place of (VII-1) to obtain 2.18 g (yield98%) of 4-(2-(2S-methylbutanoyloxy)ethyl)phenol (B-6).

[α]_(D) ²⁰ =+33.8° (c=1, CHCl₃),

n_(D) ²⁰ 1.5066.

Preparation Examples 7-8 (starting materials)

Reaction, aftertreatment and purification were carried out in the samemanner as in Preparation Example 6 except that optically activealiphatic carboxylic acids (XIX) as shown in Table (ii) were used inplace of 2S-methylbutanoic acid. The results are shown in Table (ii).

                                      TABLE (ii)                                  __________________________________________________________________________         Optically active                                                                           Optically active benzyloxy                                                                    Optically active                            Prepa-                                                                             aliphatic carboxylic                                                                       phenyl compound (VII)                                                                         phenols (V)                                 ration                                                                             acid (XIX)           Yield and        Yield and                          Example                                                                            Name   Amount                                                                              Name    properties                                                                            Name     properties                         __________________________________________________________________________    7    4S-propoxy-                                                                          3.17 g                                                                              1-benzyloxy-4-                                                                        5.96 g (87%)                                                                          4-(2-(2S-propoxy-                                                                      2.40 g (95%)                            propionic                                                                            (24 mmol)                                                                           (2-(2S-propoxy-                                                                       [α].sub.D.sup.20 +6.1°                                                   propanoyl)ethyl)-                                                                      [α].sub.D.sup.20                                                        +19.6°                           acid         propanoyl)-                                                                           (c = 1, CHCl.sub.3)                                                                   phenole (V-7)                                                                          (c = 1, CHCl.sub.3)                                  ethyl)benzene                                                                         n.sub.D.sup.20 1.5281                                                                          n.sub.D.sup.20 1.5063                                (VII-7)                                                     8    2S-chloro-                                                                           3.61 g                                                                              1-benzyloxy-4-                                                                        6.21 g (86%)                                                                          4-(2-(2S-chloro-                                                                       2.46 g (91%)                            3S-methyl-                                                                           (24 mmol)                                                                           (2-(2S-chloro-                                                                        [α].sub.D.sup.20 -4.0°                                                   3S-methyl-                                                                             [α].sub.D.sup.20                                                        -8.1°                            pentanoic    3S-methyl-                                                                            (c = 1, CHCl.sub.3)                                                                   pentanoyl)ethyl)-                                                                      (c = 1, CHCl.sub.3)                     acid                                                                     entanoyl)-                                                                         n.sub.D.sup.20 1.5382                                                                phenole (V-8)                                                                       n.sub.D.sup.20 1.5178                                                         ethyl)benzene                                                                 (VII-8)                                                     __________________________________________________________________________

Preparation Example 9 (starting materials)

Reaction, aftertreatment and purification were carried out in the samemanner as in Preparation Example 1 except that1-benzoyl-4-(4-hyxroxybutyl)benzene was used in place of1-benzyloxy-4-(3-hydroxypropyl)benzene to obtain 5.72 g (yield 84%) of1-benzyloxy-4-(4-(2S-methylbutanoyl)butyl)benzene (VII-9).

[α]_(D) ²⁰ =+7.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5322.

Further, reaction, aftertreatment and purification were carried out inthe same manner as in Preparation Example 1 except that the aboveobtained (VII-9) was used in place of (VII-1) to obtain 2.40 g (yield96%) of 4-(4-(2S-methylbutanoyloxy)butyl)phenol (V-9).

[α]_(D) ²⁰ =+29.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5049.

Preparation Examples 10-11 (starting materials)

Reaction, aftertreatment and purification were carried out in the samemanner as in Preparation Example 9 except that optically activealiphatic carboxylic acids (XIX) a shown in Table (iii) were used inplace of 2S-methylbutanoic acid. The results are shown in Table (iii).

                                      TABLE (iii)                                 __________________________________________________________________________         Optically active                                                                           Optically active benzyloxy                                                                    Optically active                            Prepa-                                                                             aliphatic carboxylic                                                                       phenyl compound (VII)                                                                         phenols (V)                                 ration                                                                             acid (XIX)           Yield and        Yield and                          Example                                                                            Name   Amount                                                                              Name    properties                                                                            Name     properties                         __________________________________________________________________________    10   2S-propoxy-                                                                          3.17 g                                                                              1-benzyloxy-4-                                                                        6.15 g (83%)                                                                          4-(4-(2S-propoxy-                                                                      2.69 g (96%)                            propionic                                                                            (24 mmol)                                                                           (4-(2S-propoxy-                                                                       [α].sub.D.sup.20 +5.5°                                                   propanoyl)butyl)-                                                                      [α].sub.D.sup.20                                                        +17.6°                           acid         propanoyl)-                                                                           (c = 1, CHCl.sub.3)                                                                   phenole (V-10)                                                                         (c = 1, CHCl.sub.3)                                  butyl)benzene                                                                         n.sub.D.sup.20 1.5249                                                                          n.sub.D.sup.20 1.5044                                (VII-10)                                                    11   2S-chloro-                                                                           3.61 g                                                                              1-benzyloxy-4-                                                                        6.61 g (85%)                                                                          4-(4-(2S-chloro-                                                                       2.69 g (90%)                            3S-methyl-                                                                           (24 mmol)                                                                           (4-(2S-chloro-                                                                        [α].sub.D.sup.20 -3.1°                                                   3S-methyl-                                                                             [α].sub.D.sup.20                                                        -7.2°                            pentanoic    3S-methyl-                                                                            (c = 1, CHCl.sub.3)                                                                   pentanoyl)butyl)-                                                                      (c = 1, CHCl.sub.3)                     acid         pentanoyl)-                                                                           n.sub.D.sup.20 1.5320                                                                 phenole (V-11)                                                                         n.sub.D.sup.20 1.5143                                butyl)benzene                                                                 (VII-11)                                                    __________________________________________________________________________

Preparation Example 12 (starting materials)

84.0 g (0.63 mol) of aluminum chloride and 400 ml of dichloromethanewere charged in a four-necked flask provided with a stirrer and athermometer and then thereto was added 51.8 g (0.66 mol) of acetylchloride at 10°-20° C. over a period of 2 hours. This was kept at thattemperature for 1 hour and then thereto was added 49.2 g (0.3 mol) ofβ-phentyl acetate at 10°-25° C. over a period of 3 hours. The contentwas kept at 20°-30° C. and then was taken out into ice water and 100 mlof dichloromethane was added thereto to separate an organic layer. Thisorganic layer was washed with water, 3% aqueous sodium carbonatesolution and water in succession, dried over magnesium sulfate and thenconcentrated under reduced pressure to obtain 43.0 g (yield 93%) of4-(β-acetoxyethyl)acetophenone (XVI-12).

51.5 g (0.25 mol) of the resulting 4-(β-acetoxyethyl)acetophenone(XVI-12), 65 g of 20% sodium hydroxide and 150 ml of methanol werecharged in the flask and stirred at room temperature for 4 hours. Aftercompletion of the reaction, the reaction mixture was poured into waterand extracted with 200 ml of toluene. Organic layer separated was washedwith water and then concentrated under reduced pressure to obtain 40.6 g(yield 99%) of 4-(β-hydroxyethyl)acetophenone (XV-12).

Subsequently, 7.88 g (0.048 mol) of the resulting (XV-12) and 80° C.Thereto was added 1.16 g (0.048 mol) of sodium hydride and this was keptat that temperature for 1 hour and additionally for 2 hours at 20° C.Then, thereto was added 12.1 9 (0.05 mol) of 2S-methylbutyl tosylate at15°-25° C. over a period of 30 minutes and this was kept at thattemperature for 30 minutes and then for 2 hours at 30°-35° C. Aftercompletion of the reaction, the reaction mixture was poured into icewater and extracted with 60 ml of ethyl acetate. The organic layer wasseparated, washed with water and concentrated under reduced pressure andpurified by column chromatography using toluene to obtain 7.30 g (yield65%) of 4-{2-(2S-methylbutoxy)ethyl}acetophenone (VI-12).

[α]_(D) ²⁰ =+4.5° (c=1, CHCl₃),

n_(D) ²⁰ =1.5118.

Then, 2.34 g (0.01 mol) of the obtained (VI-12), 3.44 g (0.02 mol) ofmeta-chloroperbenzoic acid and 20 ml of dichloromethane were charged inthe flask and reaction was allowed to proceed at 20°-30° C. for 24hours. The moment at which the starting material (VI-12) disappeared wastaken as a reaction end and reaction was completed.

The reaction mixture was washed with 3% sodium carbonate and then withwater and then concentrated. The concentrated residue was purified bycolumn chromatography using toluene to obtain 2.25 g (yield 90%) of4-{2-(2S-methylbutoxy)ethyl}phenylacetate (VIII-12).

[α]_(D) ²⁰ =+3.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.4982.

Subsequently, 1.25 g (5 mmols) of the obtained (VIII-12), 1.5 g (7.5mmols) of 20% sodium hydroxide and 5 ml of methanol were charged in theflask and stirred at room temperature for 4 hours. After completion ofthe reaction, methanol was distilled off and the residue was renderedweakly acidic with 2N-aqueous hydrochloric acid and extracted with 20 mlof ethyl acetate. The organic layer was washed with water and thenconcentrated under reduced pressure. The concentrated residue waspurified by chromatography using toluene:ethyl acetate=5:1 to obtain0.92 g (yield 96%) of 4-{2-(2S-methylbutoxy)ethyl}phenol (V-12).

[α]_(D) ²⁰ =+6.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5130.

Preparation Example 13 (starting materials)

7.88 g (0.048 mol) of (XV-12) obtained in Preparation Example 12 and 70ml of N-methylpyrrolidone were charged in the flask and cooled to 0°-5°C. Thereto was added 1.16 g (0.048 mol) of sodium hydride and this waskept at that temperature for 1 hour and furthermore for 2 hours at 20°C. Then, thereto was added 17.06 g (0.06 mol) of 1R-methylheptyltosylate at 15°-20° C. over a period of 2 hours and this was kept atthat temperature for 1 hour and then for 2 hours at 30°-35° C. Aftercompletion of the reaction, the reaction mixture was subjected toaftertreatment and purification as in Preparation Example 12 to obtain5.96 g (yield 45%) of 4-{-(1S-methylheptyloxy)ethyl}acetophenone(VI-13).

[α]_(D) ²⁰ =+3.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5047.

Then, 2.76 g (0.01 mol) of the resulting (VI-13), 4.3 g (0.025 mol) ofm-perchlorobenzoic acid and 20 ml of dichloroethane were charged in theflask and reaction was allowed to proceed for 20 hours at 20°-30° C.After completion of the reaction, the reaction mixture was washed with3% sodium carbonate, followed by aftertreatment and purification as inPreparation Example 12, thereby to obtain 2.69 g (yield 92%) of4-{2-(1S-methylheptyloxy)ethyl}phenylacetate (VIII-13).

[α]_(D) ²⁰ =+3.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.4966.

Thereafter, 1.46 g (5 mmols) of the obtained (VIII-13), 2.1 g (7.5mmols) of 20% potassium hydroxide, 3 ml of methanol and 1 ml oftetrahydrofuran were stirred at 30° C. for 4 hours. After completion ofthe reaction, ethanol and tetrahydrofuran were distilled off and theresidue was rendered weakly acidic with 2N-aqueous hydrochloric acid,followed by aftertreatment and purification as in Preparation Example12, thereby to obtain 1.20 g (yield 95.5%) of4-{2-(1S-methylheptyloxy)ethyl}phenol (V-13).

[α]_(D) ²⁰ =+55° (c=1, CHCl₃),

n_(D) ²⁰ =1.5102.

Preparation Example 14 (starting material)

7.88 g (0.048 mole) of the (XV-12) obtained in the Starting-materialPreparation Example 12 and 80 ml of dimethylformamide were charged,followed by cooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodiumhydride were added thereto and the resulting mixture was maintained atthe same temperature for 1 hour, the temperature was raised to roomtemperature. Subsequently, 16.34 g (0.06 mole) of 2S-propoxypropyltosylate were added dropwise. The resulting mixture was maintained atroom temperature for 1 hour and then at 25° to 30° C. for 3 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Starting-material Preparation Example 12, toobtain 6.98 g (yield: 55%) of4-{2-(2S-propoxypropoxy)ethyl}-acetophenone (VI-14).

[α]_(D) ²⁰ =+4.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5103.

Next, 2.64 g (0.01 mole ) of the VI-14) obtained above, 4.3 g (0.025mole) of methachloroperbenzoic acid and 20 ml of 1,2-dichloroethane werecharged, followed by stirring at 20° to 30° C. for 15 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Starting-material Preparation Example 12, toobtain 2.61 g (6ield: 93%) of 4-{2-(2S-propoxypropoxy)ethyl}phenylacetate (VIII-14).

[α]_(D) ²⁰ =+4.2° (c=1, CHCl₃),

n_(D) ²⁰ =1.4938.

Next, 1.40 g (5 milimole) of the (VIII-14) obtained above, 2.1 g (7.5milimole) of 20% potassium hydroxide and 5 ml of methanol were stirredat room temperature for 3 hours. After completion of the reaction, themethanol was distilled off and post-treatment and purification werecarried out similarly to in the Starting-material Preparation Example12, to obtain 1.17 g (yield: 98%) of4-{2-(2S-propoxypropoxy)ethyl}phenol (V-14).

[α]_(D) ²⁰ =+7.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.5087.

Preparation Example 15 (starting material)

Into an apparatus similar to in the Starting-material PreparationExample 12, 84.0 g (0.63 mole) of aluminum chloride and 450 ml ofdichloromethane were charged, followed by adding 51. 8 g (0.66 mole) ofacetyl chloride at 10° to 15° C. over 2 hours. After maintained at thesame temperature for 1 hour, 53.4 g (0.3 mole) of 3-phenylpropyl acetatewere added thereto at 10° to 20° C. over 3 hours. After maintained at25° C. for 4 hours, the reaction mixture was poured into ice-water,followed by addition of 100 ml of dichloromethane to separate theorganic phase. The organic phase was washed subsequently with water, 3%aqueous sodium carbonate solution and water. The organic phase was driedover magnesium sulfate and then concentrated under reduced pressure toobtain 62.4 g (yield: 94.5%) of 4-(3-acetoxypropyl)acetophenone (XVI-15)

55.0 g (0.25 mole) of the (XVI-15) obtained above, 65 g of 10% potassiumhydroxide, 20 ml of tetrahydrofuran and 60 ml of methanol were charged,followed by stirring at room temperature for 5 hours. After completionof the reaction, the reaction mixture was concentrated under reducedpressure to distill the tetrahydrofuran and methanol off. The residuewas extracted with toluene. The organic phase was further washed withwater and then concentrated under reduced pressure to obtain 43.9 g(yield: 98.5%) of 4-(3-hydroxypropyl)acetophenone (XV-15).

Next, 8.54 g (0.-48 mole) of the XV-15) obtained above and 80 ml ofdimethylformamide were charged, followed by cooling to 0° to 5° C. After1.16 g (0.048 mole) of sodium hydride were added thereto, the resultingmixture was maintained at the same temperature for 1 hour and further at25° C. for 2 hours. Subsequently, 12.1 g (0.05 mole) of 2S-methylbutyltosylate were added thereto at 20° to 30° C. over 3 hours. The resultingmixture was maintained at the same temperature for 30 minutesand then at30° to 40° C. for 2 hours. After completion of the reaction,post-treatment and purification were carried out similarly to in theStarting-material Preparation Example 12, to obtain 8.44 g (yield: 71%)of 4-{3-(2S-methylbutoxy)propyl}acetophenone (VI-15).

[α]_(D) ²⁰ =+3.3° (c=1, CHCl₃),

n_(D) ²⁰ =1 5048.

Next, to a solution of 2.48 g (0.01 mole) of the (VI-15) obtained aboveand 20 ml of propyl ether, were added 1.14 g of 60% peracetic acid at20° C. over 2 hours, followed by stirring at 20° to 30° C. for 15 hours.After completion of the reaction, the reaction mixture was washedsubsequently with water, 2% aqueous sodium carbonate solution, water, 2%aqueous hydrochloric acid solution and water. Subsequently, similarly toin the Starting-material Preparation Example 12, post-treatment andpurification were carried out to obtain 2.44 g (yield: 92.5%) of4-{3-(2S-methylbutoxy)propyl}phenyl acetate (VIII-15).

[α]_(D) ²⁰ =+2.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.4923.

Next, 1.32 g (5 millimole) of the VIII-15) obtained above, 2 g (0.01mole) of 20% sodium hydroxide and 0.1 g of tetrabutylammonium bromidewere stirred at 30° C. for 10 hours. After completion of the reaction,the reaction mixture was adjusted to weak acidic with 2N-aqueoushydrochloric acid solution and extracted with 20 ml of ethyl acetate.Subsequently, similarly to in the Starting-material Preparation Example12, post-treatment and purification were carried out to obtain 1.06 g(yield: 95.5%) of 4-{3-(2S-methylbutoxy)propyl}phenol (V-15).

[α]_(D) ²⁰ =+3.5° (c=1, CHCl₃),

n_(D) ²⁰ =1.5070

Preparation Example 16 (starting material)

8.54 g (0.048 mole) of the (XV-15) obtained in the Starting-materialPreparation Example 15, 20 ml of tetrahydrofuran and 60 ml ofdimethylformamide were charged, followed by cooling to 0° to 10° C.After 1.28 g (0.052 mole) of sodium hydride were added thereto, theresulting mixture was maintained at the same temperature for 1 hour andfurther at 20° C. for 2 hours.

Next, 17.06 g (0.06 mole) of 1R-methylheptyl tosylate were added theretoat 15° C. over 3 hours. The resulting mixture was maintained at the sametemperature for 1 hour and then at 30° C. for 1 hour. After completionof the reaction, post-treatment and purification were carried outsimilarly to in the Starting-material Preparation Example 12 to obtain6.68 g (yield 48%) of 4-{3-(1S-methylheptyloxy)propyl}acetophenone(VI-16).

[α]_(D) ²⁰ =+3.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5020.

Next, 2.9 g (0.01 mole) of (VI-16) obtained above, 4.3 g (0.025 mole) ofmethachloroperbenzoic acid and 15 ml of dichloromethane were charged toreact with each other at 20° to 30° C. for 24 hours. After completion ofthe reaction, the reaction mixture was washed subsequently with 3%sodium hydroxide and water. The organic phase was concentrated and thenpurified by column chromatography to obtain 2.83 g (yield: 92.4%) of4-{3-(1S-methylheptyloxy)propyl}acetate (VIII-16).

[α]_(D) ²⁰ =+2.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5019.

Next, 1.53 g (5 millimole) of the (VIII-16) obtained above, 3 g (0.015mole) of 20% sodium hydroxide and 5 ml of methanol were stirred at 20°to 30° C. for 5 hours. After completion of the reaction, the methanolwas distilled off and the residue was adjusted to weak acidic with2N-aqueous hydrochloric acid solution and extracted with 20 ml of ethylacetate. The organic phase was washed with water and then concentratedunder reduced pressure. The concentrated residue was purified by columnchromatography with toluene:ethyl acetate (5:1) to obtain 1.27 g (yield:96.5%) of 4-{3-(1S-methylheptyl)propyl}phenol (V-16).

[α]_(D) ²⁰ =+4.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.5051.

Preparation Examples 17 to 22 (Starting-material)

Reaction, post-treatment and purification were carried out similarly toin the Starting-material Preparation Example 16 except that a sulfornateshown in Table-(iv) was used in place of 1R-methylheptyltocylate, toobtain the results as shown in Table-(iv).

                                      TABLE (iv)                                  __________________________________________________________________________    Preparation                                                                         Alkylating agent                                                                             Optically active     Optically active                    Example                                                                             (XI)           acetophenone (VI)    acetoyloxybenzene (VIII)            (starting      Amount           Yield and            Yield and                material)                                                                           Name     used  Name       Physical properties                                                                     Name       Physical                 __________________________________________________________________________                                                         properties               17    2S-butyltosylate                                                                       13.7 g                                                                              4-{3-(2R-  4.5 g     4-{3-(2R-  2.29 g                                  (0.06 mole)                                                                         butoxy)propyl}-                                                                          (yield 40%)                                                                             butoxy)propyl}-                                                                          (yield 1.5%)                                  acetophenone                                                                             [α].sub.D.sup.20 -5.4°                                                     phenole acetate                                                                          [α].sub.D.sup.2                                                         0 +19.6°                               (VI-17)    n.sub.D.sup.20 1.5118                                                                   (VIII-17)  n.sub.D.sup.20                                                                1.5063                   18    4S-methylhexyl                                                                         13.52%                                                                              4-{3-(4S-  8.36 g    4-{3-(4S-  2.72 g                         tosylate (0.05 mole)                                                                         methylhexyloxy)-                                                                         (yield 63%)                                                                             methylhexyloxy)-                                                                         (yield 93.1%)                                 propyl}acetophenone                                                                      [α].sub.D.sup.20 +1.5°                                                     propyl}phenyl                                                                            [α].sub.D.sup.2                                                         0 +1.5°                                (VI-18)    n.sub.D.sup.20 1.4908                                                                   acetate (VIII-18)                                                                        n.sub.D.sup.20                                                                1.4912                   19    2S-fluoroheptyl                                                                        17.28%                                                                              4-{3-(2S-  6.36 g    4-{3-(2S-  2.81 g                         tosylate (0.06 mole)                                                                         fluoroheptyl)-                                                                           (yield 45%)                                                                             fluoroheptyloxy)-                                                                        (yield 90.4%)                                 propyl}acetophenone                                                                      [α].sub.D.sup.20 -6.2°                                                     propyl}phenyl                                                                            [α].sub.D.sup.2                                                         0 -7.2°                                (VI-19)    n.sub.D.sup.20 1.5002                                                                   acetate (VIII-19)                                                                        n.sub.D.sup.20                                                                1.4928                   20    2S-methoxypropyl                                                                       14.66%                                                                              4-{3-(2S-  6.25 g    4-{3-(2S-  2.50 g                         tosylate (0.06 mole)                                                                         methoxypropoxy)-                                                                         (yield 52%)                                                                             methoxypropyl)-                                                                          (yield 94%)                                   propyl}acetophenone                                                                      [α].sub.D.sup.20 +6.2°                                                     propyl}phenyl                                                                            [α].sub.D.sup.2                                                         0 +5.9°                                (VI-20)    n.sub.D.sup.20 1.5108                                                                   acetate (VIII-20)                                                                        n.sub.D.sup.20                                                                1.5010                   21    2S-propoxypropyl                                                                       16.34%                                                                              4-{3-(2S-  6.41 g    4-{3-(2S-  2.71 g                         tosylate (0.06 mole)                                                                         propoxypropoxy)-                                                                         (yield 48%)                                                                             propoxypropoxy)-                                                                         (yield 92%)                                   propyl}acetophenone                                                                      [α].sub.D.sup.20 +4.6°                                                     propyl}phenyl                                                                            [α].sub.D.sup.2                                                         0 +3.9°                                (VI-21)    n.sub.D.sup.20 1.4999                                                                   acetate (VIII-21)                                                                        n.sub.D.sup.20                                                                1.4927                   22    2S-octyl-                                                                              20.55%                                                                              4-{3-(2S-  6.86 g    4-{3-(2S-  3.32 g                         oxypropyl                                                                              (0.06 mole)                                                                         octyloxypropoxy)-                                                                        (yield 41%)                                                                             propoxypropoxy)-                                                                         (yield 91%)                    tosylate       propyl}acetophenone                                                                      [α].sub. D.sup.20                                                                 propyl}phenyl                                                                            [α].sub.D.sup.2                                                         0 +3.6°                                (VI-22)    n.sub.D.sup.20 1.4973                                                                   acetate (VIII-21)                                                                        n.sub.D.sup.20           __________________________________________________________________________                                                         1.4915                                                     Preparation                                                                         Optically active                                                        Example                                                                             phenol (V)                                                              (starting          Yield and                                                  material)                                                                           Name         Physical                 __________________________________________________________________________                                                         property                                                   17    4-{3-(2R-butoxy)phenyl}-                                                                   1.01 g                                                           phenol (V-17)                                                                              (yield 97.0%)                                                                 [α].sub.D.sup.2                                                         0 +19.6°                                                               n.sub.D.sup.20                                                                1.5076                                                     18    4-{3-(4S-methylhexyloxy)-                                                                  1.22 g                                                           propyl}phenol                                                                              (yield 7.5%)                                                     (V-18)       [α].sub.D.sup.2                                                         0 +2.3°                                                                n.sub.D.sup.20                                                                1.5002                                                     19    4-{3-(2S-fluoroheptyloxy)-                                                                 1.27 g                                                           propyl}phenol                                                                              (yield 94.5%)                                                    (V-19)       [α].sub.D.sup.2                                                         0 -7.3°                                                                n.sub.D.sup.20                                                                1.5010                                                     20    4-{3-(2S-methoxypropoxy)-                                                                  1.18 g                                                           propyl}phenol                                                                              (yield 98%)                                                      (V-20)       [α].sub.D.sup.2                                                         0 +10.1°                                                               n.sub.D.sup.20                                                                1.5112                                                     21    4-{3-(2S-octyloxypropoxy)-                                                                 1.30 g                                                           propyl}phenol                                                                              (yield 97%)                                                      (V-21)       [α].sub.D.sup.2                                                         0 +7.0°                                                                n.sub.D.sup.20                                                                1.5012                                                     22    4-{3-(2S-octyloxypropoxy)-                                                                 1.62 g                                                           propyl}phenol                                                                              (yield 96%)                                                      (V-22)       [α].sub.D.sup.2                                                         0 +5.6°                                                                n.sub.D.sup.20           __________________________________________________________________________                                                         1.5004                    Optical rotation was each measured under conditions of (c = 1,                CHCl.sub.3).                                                             

Preparation Example 23 (starting-material)

Similarly to in Preparation Example 12 (starting material), 84.0 g (0.63mole) of aluminum chloride and 500 ml of dichloroethane were charged,followed by adding 51.8 g (0.66 mole) of acetyl chloride at 10° to 15°C. over 3 hours. After maintained at the same temperature for 1 hour,57.6 g (0.3 mole) of 4-phenylbutyl acetate were added thereto at 10° to20° C. over 3 hours. After maintained at 20° to 25° C. for 3 hours, thereaction mixture was poured into ice-water and dichloromethane was addedthereto to effect extraction. Subsequently, similarly to in thePreparation Example 12 (starting material), post-treatment andpurification were carried out to obtain 59.0 g (yield: 84%) of4-(4-acetoxybutyl)acetophenone (XVI-23).

58.5 g (0.25 mole) of the (XVI-23) obtained above, 75 g of 20% sodiumhydroxide and 150 ml of methanol were charged, followed by stirring atroom temperature for 5 hours. Subsequently, similarly to in thePreparation Example 12 (starting material), post-treatment andpurification were carried out to obtain 40.8 g (yield: 85%) of4-(4-hydroxybutyl)acetophenone (XV-23).

Next, 9.22 g (0.048 mole) of the (XV-23) obtained above, 60 ml ofdimethylformamide and 15 ml of tetrahydrofuran were charged, followed bycooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodium hydride wereadded thereto, the resulting mixture was maintained at the sametemperature for 1 hour and further at 25° to 30° C. for 2 hours.Subsequently, 12.1 g (0.05 mole) of 2S-methylbutyl tosylate were addedat 15° to 25° C. over 3 hours. The reaction mixture was maintained atthe same temperature for 1 hour and further at 30° to 35° C. for 2hours. After completion of the reaction, post-treatment and purificationwere carried out similarly to in the Preparation Example 12 (startingmaterial), to obtain 8.94 g (yield: 71%) of4-{4-(2S-methylbutoxy)butyl}acetophenone (VI-23).

[α]_(D) ²⁰ =+1.6° (c=1, CHCl₃),

n_(D) ²⁰ =1.5020.

Next, 2.62 g (0.01 mole) of the (VI-23) obtained above, 3.44 g (0.02mole) of metha-chloroperbenzoic acid and 12 ml of ethyl acetate werecharged to react with each other a 25° to 35° C. for 20 hours. Aftercompletion of the reaction, the reaction mixture was washed subsequentlywith 3% sodium carbonate and water. The organic phase was concentratedand then purified by column chromatography to obtain 2.52 g (yield:90.5%) of 4-{4-(2S-methylbutoxy)butyl}phenyl acetate (VIII-23).

[α]_(D) ²⁰ =+1.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.4896.

Next, 1.39 g (5 millimole) of the (VIII-23) obtained above, 3 g (0.015mole) of 20% sodium hydroxide and 3 ml of methanol were stirred at 25°to 30° C. for 5 hours. Subsequently, similarly to in Preparation Example12 (starting material), post-treatment and purification were carried utto obtain 1.13 g (yield: 95.5%) of 4-{4-(2S-methylbutoxy)butyl}phenol(V-23).

[α]_(D) ²⁰ =+2.9° (c=1, CHCl₃),

n_(D) ²⁰ =1.5030.

Preparation Example 24 (starting material)

9.22 g (0.048 mole) of the (XV-23) obtained in Preparation Example 23(starting material) and 80 ml of dimethylformamide were charged,followed by cooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodiumhydride were added thereto and the resulting mixture was maintained atthe same temperature for 1 hour, the temperature was raised to roomtemperature. Subsequently, 16.34 g (0.06 mole) of 2S-propoxypropyltosylate were added dropwise. The resulting mixture was maintained atroom temperature for 1 hour and then at 25° to 30° C. for 3 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Preparation Example 12 (starting material), toobtain 8.7 g (yield: 62%) of 4-{4-(2S-propoxypropoxy)butyl}acetophenone(VI-24).

[α]_(D) ²⁰ =+4.2° (c=1, CHCl₃),

n_(D) ²⁰ =1.4990.

Next, 2.92 g (0.01 mole) of the (VI-24) obtained above, 4.3 g (0.025mole) of meta-chloroperbenzoic acid and 20 ml of 1,2-dichloroethane werecharged, followed by stirring at 20° to 30° C. for 20 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Preparation Example 12 starting material, toobtain 2.84 g (yield: 92%) of 4-{4-(2S-propoxypropoxy)butyl}phenylacetate (VIII-24).

[α]_(D) ²⁰ =+3.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.4927.

Next, 1.54 g (5 millimole) of the (VIII-24) obtained above, 3 g (0.015mole) of 20% sodium hydroxide and 5 ml of methanol were stirred at roomtemperature for 3 hours. Subsequently, similarly to the PreparationExample 12 (starting material), post-treatment and purification werecarried out to obtain 1.38 g (yield: 98%) of4-{4-(2S-propoxypropoxy)butyl}phenol (V-24).

[α]_(D) ²⁰ =+6.6° (c=1, CHCl₃),

n_(D) ²⁰ =1.5080.

Preparation Example 25 (starting material)

Alkylating reaction, post-treatment and purification were carried outsimilarly to in Preparation Example 15 (starting material) except that10.88 g (0.072 mol) of 2S-methylbutyl bromide was used in place of2S{ketylbutyl tosylate to obtain 7.62 g (yield 64%) of4-{3-(2S-methylbutoxy)propyl}acetophenone (VI-25).

2.48 g (0.01 mole) of the (VI-25) obtained above was subjected tooxidizing reaction similarly to in the Preparation Example 15 (startingmaterial) to give 4-{3-(2S-methylbutoxy)phenyl}phenyl acetate (VIII-25).The obtained amount was 2.46 g (yield: 93%).

Further, 1.32 g (5 millimole) of the (VIII-25) mentioned above wassubjected to hydrolyzing reaction similarly to the Preparation Example14 (starting material), to give 4-{3-(2S-methylbutoxy)propyl}phenol(V-25). The obtained amount was 1.06 g (yield: 95.3%).

Preparation Example 26 (starting material)

Into a four necked flask equiped with a stirrer and a thermometer, 84.0g (0.63 mole) of aluminum chloride and 400 ml of dichloroethane werecharged, followed by adding 51.8 g (0.66 mole) of acetyl chloride at 10°to 20° C. over 2 hours. After maintained at the same temperature for 1hour, 49.2 g (0.3 mole) of β-phenetyl acetate were added thereto at 10°to 25° C. over 3 hours. After maintained at 20° to 30° C., the reactionmixture was poured in to ice-water and 100 ml of dichloromethane wasadded thereto to separate the organic phase. The organic phase waswashed subsequently with water, 3% aqueous sodium carbonate solution andwater. The organic phase was dried over magnesium sulfate to obtain 43.0g (yield 93%) of of 4-(β-acetoxyethyl)acetophenone (XVI-26).

51.5 g (0.25 mole) of the 4-(β-acetoxyethyl)acetophenone (XVI-26)obtained above, 65 g of 20% sodium hydroxide and 150 ml of methanol werecharged, followed by stirring at room temperature for 4 hours. Aftercompletion of the reaction, the reaction mixture was poured into waterto extract with 200 ml of toluene. The organic phase as washed withwater and then concentrated under reduced pressure to obtain 40.6 g(yield: 99%) of 4-(β-hydroxyethyl)acetophenone (XV-26).

Next, 7.88 g (0.048 mole) of the (XV-26) obtained above and 80 ml ofdimethylformamide were charged, followed by cooling to 0° to 5° C. After1.16 g (0.048 mole) of sodium hydride were added thereto, the resultingmixture was maintained at the same temperature for 1 hour and further at20° C. for 2 hours. Subsequently, 12.1 g (0.05 mole) of 2S-methylbutyltosylate were added at 15° to 25° C. over 2 hours. The reaction mixturewas maintained at the same temperature for 30 minutes and further at 30°to 35° C. for 2 hours. After completion of the reaction, the reactionmixture was poured into ice and extracted twice with 60 ml of ethylacetate. The organic phase was separated, washed with water andconcentrated under reduced pressure. The concentrated residue waspurified by column chromatography with toluene to obtain 7.30 g (yield:65%) of 4-{2-(2S-methylbutoxy)ethyl}acetophenone (VI-26).

[α]_(D) ²⁰ =+4.5° (c=1, CHCl₃),

n_(D) ²⁰ =1.5118.

Next, 2.34 g (0.0o mole) of the (VI-26) obtained above was added at roomtemperature to a mixed solution previously obtained by adding 11 g (0.07mole) of bromine to 16 g of 20% aqueous sodium hydroxide solution andfurther adding 30 ml of dioxane, followed by stirring for 15 hours.After completion of the reaction, the reaction mixture was poured intoice-water, adjusted to weak acidic with 10% sulfuric acid and extractedwith 100 ml of ethyl acetate. The organic phase was separated andfurther washed with water and then concentrated. The concentratedresidue was purified by chromatography with toluene-acetic acid (20 : 1)to obtain 2.1 g (yield: 90%) of 4-{2-(2S-methylbutoxy)ethyl}benzoic acid(III-26). [α]_(D) ²⁰ =+6.1° (c=1, CHCl₃),

m.p. 60° to 62° C.

Preparation Example 27 (starting material)

7.88 g (0.048 mole) of the (XV-26) obtained in the Preparation Example26 (starting material) and 70 ml of N-methylpyrrolidone were chargedfollowed by cooling to 0° to 5° C. After 1.16 g of (0.048 mole) ofsodium hydride were added thereto, the resulting mixture was maintainedat the same temperature for 1 hour and further at 20° C. for 2 hours.Subsequently, 17.06 g (0.06 mole) of 1R-methylheptyl tosylate were addedat 15° to 20° C. over 2 hours. The resulting mixture was maintained atthe same temperature for 1 hour and then at 30° to 35° C. for 2 hours.After completion of the reaction, post-treatment and purification werecarried out similarly to in the Preparation Example 26 (startingmaterial), to obtain 5.96 g (yield: 45%) of4-{2-(1S-methylheptyloxy)ethyl}acetophenone (VI-27).

[α]_(D) ²⁰ =+3.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5047.

Next, 2.76 g (0.01 mole) of the (VI-27) obtained above was added at roomtemperature to a mixed solution of 16 ml of 20% aqueous sodium hydroxidesolution, 11 g (0.07 mole) of bromine and 20 ml of dioxane, followed bystirring for 20 hours. After completion of the reaction, post-treatmentand purification were carried out similarly to in the PreparationExample 12 ;starting material), to obtain 2.56 g (yield: 92%) of4-(β-(1S-methylheptyloxy)ethyl)benzoic acid (III-27).

[α]_(D) ²⁰ +4.9° (c=1, CHCl₃),

m.p. 41° to 43° C.

Preparation Example 28 (starting material)

7.88 g (0.048 mole) of the (XV-26) obtained in Preparation Example 26(starting material) and 80 ml of dimethylformamide were charged,followed by cooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodiumhydride were added thereto and the resulting mixture was maintained atthe same temperature for 1 hour, the temperature was raised to roomtemperature. Subsequently, 16.34 g (0.06 mole) of 2S-propoxypropyltosylate were added dropwise. The resulting mixturw as maintained atroom temperature for 1 hour and then at 25° to 30° C. for 3 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Preparation Example 12 (starting material), toobtain 6.98 g (yield: 55%) of 4-{2-(2S-propoxypropoxy)ethyl}acetophenone(VI-28).

[α]_(D) ²⁰ =+4.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5003.

Next, 2.64 g (0.01 mole) of the (VI-28) obtained above were added atroom temperature to a mixed solution of 16 ml of 20% aqueous sodiumhydroxide solution, 11 g (0.07 mole) of bromine and 20 ml of dioxane,followed by stirring for 20 hours. After completion of the reaction,post-treatment and purification were carried out similarly to in thePreparation Example 26 (starting-material), to obtain 2.47 g (yield:93%) of 4-{2-(2S-propoxyproozy)ethyl}benzoic acid (III-28).

[α]_(D) ²⁰ +6.0° (c=1, CHCl₃),

m.p. 51° to 52° C.

Preparation Example 29 (starting material)

Into an apparatus similar to in the Preparation Example 26 (startingmaterial), 84.0 g (0.63 mole) of aluminum chloride and 450 ml ofdichloromethane were charged followed by adding 51.8 g (0.66 mole) ofacetyl chloride at 10° to 15° C. over 2 hours. After maintained at thesame temperature for 1 hour, 53.4 g (0.3 mole) of 3-phenylproyl acetatewere added thereto 10° to 20° C. over 3 hours. After maintained at 25°C. for 4 hours, the reaction mixture was poured into ice-water, followedby addition of 100 ml of dichloromethane to separate the organic phase.The organic phase was washed subsequently with water, 3% aqueous sodiumcarbonate solution and water. The organic phase was dried over magnesiumsulfate and then concentrated under reduced pressure to obtain 62.4 g(yield: 94.5%) of 4-(3-acetoxypropyl)acetophenone (XVI-29).

55.0 g (0.25 mole) of the (XVI-29) obtained above, 65 g of 10% potassiumhydroxide, 20 ml of tetrahydrofuran and 60 ml of methanol were charged,followed by stirring at room temperature for 5 hours. After completionof the reaction, the reaction mixture was concentrated under reducedpressure to distill the tetrahydrofuran and methanol off. The residuewas extracted with toluene. The organic phase was further washed withwater and then concentrated under reduced pressure to obtain 43.9 g(yield: 98.5%) of 4-(3-hydroxypropyl)acetophenone (XV-29).

Next, 8.54 g (0.048 mole) of the (XV-29) obtained above and 80 ml ofdimethylformamide were charged, followed by cooling to 0° to 5° C. After1.16 g (0.048 mole) of sodium hydride were added thereto, the resultingmixture was maintained at the same temperature for 1 hour and further at25° C. for 2 hours. Subsequently, 12.1 g (0.05 mole) of 2S-methylbutyltosylate were added at 20° to 30° C. over 3 hours. The resulting mixturewas maintained at the same temperature for 30 minutes and then at 30° to40° C. for 2 hours.

After completion of the reaction, post-treatment and purification werecarried out similarly to in the Preparation Example 26 (startingmaterial), to obtain 8.44 g (yield: 71%) of4-{3-(2S-methylbutoxy)propyl}acetophenone (VI-29).

[α]_(D) ²⁰ =+3.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.5048.

Next, similarly to in Preparation Example 26 (starting material) 2.48 g(0.01 mole) of the (VI-29) obtained above were added to a mixed solutionof 18 ml of 20% aqueous sodium hydroxide solution, 11 g (0.07 mole) ofbromine and 20 ml of dioxane, followed by stirring for 24 hours.

Subsequently, similarly to in the Preparation Example 26 (startingmaterial), post-treatment and purification were carried out to obtain2.25 g (yield: 90.5%) of 4-{3-(2S-methylbutoxy)propyl}-benzoic acid(III-29).

[α]_(D) ²⁰ =+4.6° (c=1, CHCl₃),

m.p. 49.5° to 51° C.

Preparation Example 30 (starting material)

8.54 g (0.048 mole) of the (XV-29) obtained in Preparation Example 29(starting material), 10 ml of tetrahydrofuran and 30 ml ofdimethylformamide were charged, followed by cooling to 0° to 5° C. After1.28 g (0.052 mole) of sodium hydride were added thereto, the resultingmixture was maintained at the same temperature for 1 hour and further at20° C. for 2 hours.

Sequently, 17.06 g (0.06 mole) of 1R-methylheptyl tosylate were added at15° C. over 3 hours. The resulting mixture was maintained at the sametemperature for 1 hour and then at 30° C. for 1 hour. After completionof the reaction, post-treatment and purification were carried outsimilarly to in the Preparation Example 26 (starting material), toobtain 6.68 g (yield: 48%) of4-{3-(1S-methylheptyloxy)propyl}acetophenone (VI-30).

[α]_(D) ²⁰ =+3.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5020.

Next, 2.9 g (0.01 mole) of the (VI-30) obtained above were added to amixed solution of 18 ml of 20% aqueous sodium hydroxide solution, 11 g(0.07 mole) of bromine and 30 ml of dioxane, followed by stirring for 24hours.

Subsequently, similarly to in the Preparation Example 26 (startingmaterial), post-treatment and purification were carried out to obtain2.66 g (yield: 91%) of 4-{3-(1S-methylheptyloxy)propyl}benzoic acid(III-30).

[α]_(D) ²⁰ =+3.6° (c=1, CHCl₃),

m.p. 39° to 40° C.

Preparation Examples 31 to 36 (starting material)

Reaction, post-treatment and purification were carried out similarly toin the Preparation Example 30 (starting-material) except that asulfonate as shown in Table-(v) was used in place of IR-methylheptyltosylate, to obtain the results as shown in Table-(v).

                                      TABLE (v)                                   __________________________________________________________________________    Prepa-                             Optically active carboxylic                ration                                                                             Alkylating agent                                                                            Acetophenone (VI)                                                                             acid compound (III)                        Example                                                                            (XI)                   Yield and       Yield and                         (starting   Amount          Physical        Physical                          material)                                                                          Name   used   Name     properties                                                                           Name     properties                        __________________________________________________________________________    31   2S-butyl-                                                                            13.7 g 4-{3-(2R-butoxy)-                                                                      4.5 g  4-{3-(2R-                                                                              2.13 g                                 tosylate                                                                             (0.06 mmol)                                                                          propyl}-aceto-                                                                         (yield 40%)                                                                          butoxy)propyl}-                                                                        (yield 90%)                                          phenone (VI-31)                                                                        [α].sub.D.sup.20 -5.4°                                                  benzoic acid                                                                           [α].sub.D.sup.20                                                        -6.2°                                                  n.sub.D.sup.20 1.5058                                                                (III-31) m.p. 63˜65° C.       32   4S-methyl-                                                                           13.52 g                                                                              4-{3-(4S-methyl-                                                                       8.36 g 4-{3-(4S-                                                                              2.59 g                                 hexyl  (0.05 mmol)                                                                          hexyloxy)propyl}-                                                                      (yield 63%)                                                                          methylhexyloxy)-                                                                       (yield 93%)                            tosylate      benzoic acid                                                                           [α].sub.D.sup.20 +1.4°                                                  propyl}-benzoic                                                                        [α].sub.D.sup.20                                                        +2.3°                                         (VI-32)  n.sub.D.sup.20 1.4998                                                                acid (III-32)                                                                          n.sub.D.sup.20 1.4996             33   2S-fluoro-                                                                           17.28 g                                                                              4-{3-(2S-fluoro-                                                                       6.36 g 4-{3-(2S-                                                                              2.64 g                                 heptyl (0.06 mmol)                                                                          heptyloxy)-                                                                            (yield 45%)                                                                          fluoroheptyloxy)-                                                                      (yield 89%)                            tosylate      propyl}-aceto-                                                                         [α].sub.D.sup.20 -6.9°                                                  porpyl}-benzoic                                                                        [α].sub.D.sup.20                                                        -7.1°                                         phenone (VI-33)                                                                        n.sub.D.sup.20 1.4986                                                                acid (III-33)                                                                          n.sub.D.sup.20 1.5046             34   2S-methyl-                                                                           14.66 g                                                                              4-{3-(2S-methoxy-                                                                      6.25 g 4-{3-(2S-                                                                              2.37 g                                 propyl (0.06 mmol)                                                                          propoxy)propyl}-                                                                       (yield 52%)                                                                          methoxypropoxy)-                                                                       (yield 94%)                            tosylate      acetophenone                                                                           [α].sub.D.sup.20 +6.2°                                                  propyl}-benzoic                                                                        [α].sub.D.sup.20                                                        +6.8°                                         (VI-34)  n.sub.D.sup.20 1.5108                                                                acid (III-34)                                                                          m.p. 62˜64° C.       35   2S-propoxy-                                                                          16.34 g                                                                              4-{3-(2S-propoxy-                                                                      6.41 g 4-{3-(2S-                                                                              2.55 g                                 propyl (0.06 mmol)                                                                          propoxy)propyl}-                                                                       (yield 48%)                                                                          propoxypropoxy)-                                                                       (yield 91%)                            tosylate      acetophenone                                                                           [α].sub.D.sup.20 +4.6°                                                  propyl}-benzoic                                                                        [α].sub.D.sup.20                                                        +5.7°                                         (VI-35)  n.sub.D.sup.20 1.4999                                                                acid (III-35)                                                                          m.p. 43˜44° C.       36   2S-octyl-                                                                            20.55 g                                                                              4-{ 3-(2S-octyl-                                                                       6.86 g 4-{3-(2S-octyl-                                                                        3.15 g                                 oxypropyl-                                                                           (0.06 mmol)                                                                          oxypropoxy)-                                                                           (yield 41%)                                                                          oxypropoxy)-                                                                           (yield 90%)                            tosylate      propyl}aceto-                                                                          [α].sub.D.sup.20 +4.0°                                                  propyl}-benzoic                                                                        [α].sub.D.sup.20                                                        +4.9°                                         phenone (VI-36)                                                                        n.sub.D.sup.20 1.4973                                                                acid (III-36)                                                                          n.sub.D.sup.20                    __________________________________________________________________________                                                1.5027                             Optical rotation was each measured under conditions of (c = 1,                chcl.sub.3).                                                             

Preparation Example 37 (starting material)

Similarly to in the Preparation Example 26 (starting-material), 84.0 g(0.63 mole) of aluminum chloride and 500 ml of dichloroethane werecharged, followed by adding 51.8 g (0.66 mole) of acetyl chloride at 10°to 15° C. over 3 hours. After maintained at the same temperature for 1hour, 57.6 g (0.3 mole) of 4-phenylbutyl acetate were added thereto at10° to 20° C. over 3 hours. After maintained at 20° to 25° C. for 3hours, the reaction mixture was poured into ice-water and dichloroethanewas added thereto to effect extraction. Subsequently, similarly to inthe Preparation Example 26(starting material), post-treatment andpurification were carried out to obtain 56.2 g (yield: 80%) of4-(4-acetoxybutyl)acetophenole (XVI-37).

58.5 g (0.25 mole) of the (XVI-37) obtained above, 75 g of 20% sodiumhydroxide and 150 ml of methanol were charged, followed by stirring atroom temperature for 5 hours. Subsequently, similarly to in PreparationExample 26 (starting material) post-treatment and purification werecarried out to obtain 40.8 g (yield: 85%) of4-(4-hydroxybutyl)acetophenone (XV-37).

Next, 9.22 g (0.048 mole) of the (XV-37) obtained above, 60 ml ofdimethylformamide and 15 ml of tetrahydrofuran were charged, followed bycooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodium hydride wereadded thereto, the resulting mixture was maintained at the sametemperature for 1 hour and further at 25° to 30° C. for 2 hours.Subsequently, 12.1 g (0.05 mole) of 2S-methylbutyl tosylate were addedat 15° to 25° C. over 3 hours. The reaction mixture was maintained atthe same temperature for 1 hour and further at 30° to 35° C. for 2hours.

After completion of the reaction, post-treatment and purification werecarried out similarly to in the Preparation Example 26 (startingmaterial), to obtain 8.94 g (yield: 71%) of4-{4-(2S-methylbutoxy)butyl}acetophenone (VI-37).

[α]_(D) ²⁰ =+1.6° (c=1, CHCl₃),

n_(D) ²⁰ =1.5020.

Next, 2.62 g (0.01 mole) of the (VI-37) obtained above were addedsimilarly to in the Preparation Example 26 (starting material), to asolution of 20% aqueous sodium hydroxide solution, 11 g of (0.07 mole)of bromine and 20 ml of dioxane, followed by stirring for 24 hours.Subsequently, similarly to in the Preparation Example 26 (startingmaterial), post-treatment and purification were carried out to obtain2.43 g (yield: 92%) of 4-{-(2S-methylbutoxy)butyl}benzoic acid (III-37).

[α]_(D) ²⁰ =+2.2° (c=1, CHCl₃),

n_(D) ²⁰ =1.5046.

Preparation Example 38 (starting material)

9.22 g (0.048 mole) of the (XV-37) obtained in the Preparation Example37 (starting material) and 80 ml of dimethylformamide were charged,followed by cooling to 0° to 5° C. After 1.16 g (0.048 mole) of sodiumhydride were added thereto and the resulting mixture was maintained atthe same temperature for 1 hour, the temperature was raised to roomtemperature. Subsequently, 16.34 g (0.06 mole) of 2S-propoxypropyltosylate were added dropwise. The resulting mixture was maintained atroom temperature for 1 hour and then at 25° to 30° C. for 3 hours. Aftercompletion of the reaction, post-treatment and purification were carriedout similarly to in the Preparation Example 26 (starting material), toobtain 8.7 g (yield: 62%) of 4-{4-(2S-propoxypropoxy)butyl}acetophenone(VI-38).

[α]_(D) ²⁰ +4.2° (c=1, CHCl₃),

n_(D) ²⁰ =1.4990.

Next, 2.92 g (0.01 mole) of the (VI-38) obtained above were added atroom temperature to a mixed solution of 16 ml of 20% aqueous sodiumhydroxide solution, 11 g (0.07 mole) of bromine and 20 ml of dioxane,followed by stirring at room temperature for 20 hours. After completionof the reaction, post-treatment and purification were carried outsimilarly to in the Preparation Example 26 (starting material), toobtain 2.71 g (yield: 92%) of 4-{4-(2S-propoxypropoxy)butyl}benzoic acid(III-38).

[α]_(D) ²⁰ =+4.2° (c=1, CHCl₃),

m.p. 39° to 41° C.

Preparation Example 39 (starting material)

Alkylating reaction, post-treatment and purification were carried outsimilarly to in Preparation Example 29 (starting material) except that5.44 g (0.036 mole) of 2S-methylbutyl bromide were used in place of2S{methylbutyl tosylate to obtain 3.8 g (yield 64%) of4-[3-(2S-methylbutoxy)propyl}acetophenone (VI-39).

2.48 g (0.01 mole) of the (VI-39) obtained above were subjected toreaction similarly to in the Preparation Example 28 (starting material),to obtain 4-{3-(2S-methylbutoxy)propyl}benzoic acid (III-39). Amountobtained was 2.26 g (yield: 91%).

Preparation Example 40 (starting material)

Into a four-necked flask equipped with a strirrer and a thermometer,2.96 g (0.04 mole) of 2S-butanol and 15 ml of dimethylformamide wereadded, followed by cooling to 5° C. or lower. 0.48 g (0.02 mole) ofsodium hydride was added, followed by stirring at the same temperaturefor 1 hour and further at 20° to 25° C. for 2 hours. Subsequently, 4.58g (0.02 mole) of methyl 4-bromomethylbenzoate were added thereto at 20°to 25° C. over 1 hour, followed by stirring at the same temperature for2 hours and further at 30° to 35° C. for 2 hours. After completion ofthe reaction, the reaction mixture was poured into ice-water andextracted with 50 ml of toluene. The organic phase was washed with waterand then dried over magnesium sulfate. After the drying agent wasfiltered off, the solvent was distilled off. The concentrated residuewas purified by column chromatography with toluene to obtain 3.20 g(yield: 72%) of methyl 4-(2S-butoxymethyl)benzoate (IX-40).

[α]_(D) ²⁰ =+2.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5032.

Next, 1.11 g (5 millimole) of the (IX-40) obtained above, 1.5 g (7.5millimole) of 20% sodium hydroxide and 5 ml of methanol were chargedinto a four-necked flask, followed by stirring at room temperature for 4hours. After completion of the reaction, the methanol was distilled off,the resulting mixture was adjusted to weak acidic with 2N-aqueoushydrochloric acid solution and extracted with 20 ml of ethyl acetate.The organic phase was washed with water and then concentrated underreduced pressure. The concentrated residue was purified bychromatography with an eluting solvent of toluene:ethyl acetate=5:1, toobtain 1.01 g (yield: 97%) of 4-(2S-butoxymethyl)benzoic acid (III-40).

[α]_(D) ²⁰ =+6.7° (c=1, CHCl₃),

m.p. 46° to 48° C.

Preparation Example 41 (starting material)

As the optically active alcohol, 3.52 g (0.04 mole) of 2S-methylbutanolwas used in place of 2S-butanol, 3.52 g (0.04 mole) of 2S-methylbutanol,15 ml of N-methylpyrrolidone and 3 ml of tetrahydrofuran were added,followed by cooling to 5° C. or lower. 0.5 g (0.025 mole) of sodiumhydride was added thereto, followed by stirring at the same temperaturefor 1 hour and further at 20° to 25° C. for 2 hours. Subsequently, 4.86g (0.02 mole) of ethyl 4-bromomethylbenzoate were added thereto at 20°C. or lower over 1 hour, followed by stirring at the same temperaturefor 2 hours and further at 30° to 35° C. for 2 hours. After completionof the reaction, the reaction mixture was poured into ice and extractedwith 50 ml of toluene. Subsequently, post treatment and purificationwere carried out similarly to in the Preparation Example 40 (startingmaterial) to obtain 4.08 g (yield: 76%) of ethyl(4-(2S-methylbutoxymethyl)benzoate (IX-41).

[α]_(D) ²⁰ =+4.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.4987.

Next, 1.34 g (5 millimole) of the (IX-41) obtained above, 2.1 g (7.5millimole) of 20% potassium hydroxide, 3 ml of methanol and 1 ml oftetrahydrofuran were stirred at 30° C. for 4 hours. After completion ofthe reaction, the methanol and tetrahydrofuran were distilled off andthe resulting mixture was adjusted to weak acidic with 2N-aqueoushydrochloric acid solution. Subsequently, post treatment andpurification were carried out similarly to in the Preparation Example 40(starting material) to obtain 1.07 g (yield: 96.5%) of4-(2S-methylbutoxymethyl)benzoic acid (III-41).

[α]_(D) ²⁰ =+5.3° (c=1, CHCl₃),

m.p. 66° to 68° C.

Preparation Example 42 (starting material)

Reaction, post-treatment and purification were carried out similarly toin Preparation Example 40 (starting material) except that 6.41 g (0.02mole) of p-toluenesulfonic acid 4-hydroxymethylbenzoate were used inplace of ethyl 4-bromomethylbenzoate to obtain 3.56 g (yield: 70%) ofmethyl 4-(2S-methylbutoxy)benzoate (IX-42).

[α]_(D) ²⁰ =+5.5° (c=1, CHCl₃),

n_(D) ²⁰ =1.5004.

Next, 1.27 g (5 millimole) of the (IX-42) obtained above, 2 g (0.01mole) of 20% sodium hydroxide and 0.1 g of tetrabutylammonium bromidewere stirred at 30° C. for 10 hours. After completion of the reaction,the resulting mixture was adjusted to weak acidic with 2N-aqueoushydrochloric acid solution, followed by extraction with 20 ml of ethylacetate. Subsequently, post treatment and purification were carried outsimilarly to in the Preparation Example 40 (starting material) to obtain1.06 g (yield 95.8%) of 4-(2S-methylbutoxymethyl)benzoic acid (III-42)

[α]_(D) ²⁰ =+5.4° (c=1, CHCl₃),

m.p. 64° to 66° C.

Preparation Example 43 (starting material)

A solution of 3.32 g (0.02 mole) of methyl 4-hydroxymethylbenzoate and20 ml of dimethylformamide was cooled to 5° C. and 0.48 g (0.02 mole) ofsodium hydride was added, followed by stirring at the same temperaturefor 1 hour and further at 20° C. for 2 hours. Subsequently, 6.49 g(0.024 mole) of 4S-methylhexyl tosylate were added thereto at 20° to 25°C. over 1 hour, followed by stirring at the same temperature for 2 hoursand further at 30° to 35° C for 3 hours. After completion of thereaction, the reaction mixture was poured into ice-water and extractedwith 50 ml of toluene. Subsequently, post treatment and purificationwere carried out similarly to in the Preparation Example 40 (startingmaterail) to obtain 3.49 g (yield: 66%) of methyl4-(4S-methylhexyloxymethyl)benzoate (IX-43).

[α]_(D) ²⁰ =+2.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.4958.

Next, 1.32 g (5 millimole) of the (IX-43) obtained above, 3 g (0.015mole) of 20% sodium hydroxide and 5 ml of methanol were stirred at 20°to 30° C. for 5 hours. After completion of the reaction, the methanolwas distilled off, the resulting mixture was adjusted to weak acidicwith 2N-aqueous hydrochloric acid solution and extracted with 20 ml ofethyl acetate. The organic phase was washed with water and thenconcentrated under reduced pressure. The concentrated residue waspurified by column chromatography with toluene:ethyl acetate=5:1, toobtain 1.22 g (yield: 97.3%) of 4-(4S-methylhexyloxymethyl)benzoic acid(III-43).

[α]_(D) ²⁰ =+3.8° (c=1, CHCl₃),

m.p. 44° to 45° C.

Preparation Example 44 to 49 (starting material)

Reaction, post-treatment and purification were carried out similar to inPreparation Example 43 (starting material) except that alkylating agentsshown in Table-VI were used in place of 4S-methylhexyl tosylate toobtain the results shown in Table-VI.

                                      TABLE (VI)                                  __________________________________________________________________________    Prepa-             Optically active Optically active carboxylic               ration                                                                             Optically active                                                                            benzoate (IX)    acid compound (III)                       Example                                                                            alkylating agent (XI)  Yield and        Yield                            (starting   Amount          Physical         Physical                         material)                                                                          Name   used   Name     properties                                                                            Name     property                         __________________________________________________________________________    44   2S-methyl-                                                                           6.83 g Methyl 4-(2S-                                                                          3.40 g  4-(2S-methyl-                                                                          1.27 g                                heptyl (0.024 mole)                                                                         methylheptyl-                                                                          (yield 61%)                                                                           heptyloxymethyl)-                                                                      (yield 96%)                           tosylate      oxymethyl)-                                                                            [α].sub.D.sup.20 +3.9°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        +4.3°                                        benzoate (c = 1, CHCl.sub.3)                                                                   (III-44) (c = 1, CHCl.sub.3)                                 (IX-44)  n.sup.20.sub.D 1.5108                                                                          n.sup.20.sub.D 1.5006            45   2S-methyl-                                                                           6.83 g Methyl 4-(5S-                                                                          3.56 g  4-(2S-methyl-                                                                          1.28 g                                heptyl (0.024 mole)                                                                         methylheptyl-                                                                          (yield 64%)                                                                           heptyloxymethyl)-                                                                      (yield 96%)                           tosylate      oxymethyl)-                                                                            [α].sub.D.sup.20 +2.0°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        +2.1°                                        benzoate (c = 1, CHCl.sub.3)                                                                   (III-45) (c = 1, CHCl.sub.3)                                 (IX-45)  n.sub. D.sup.20 1.4951                                                                         n.sub.D.sup.20 1.4998            46   2S-fluoro-                                                                           7.21 g Methyl 4-(2S-                                                                          2.71 g  4-(2S-fluoro-                                                                          1.28 g                                heptyl (0.025 mole)                                                                         fluoroheptyl-                                                                          (yield 48%)                                                                           heptyloxymethyl)-                                                                      (yield 95.5%)                         tosylate      oxymethyl)-                                                                            [α].sub.D.sup.20 -5.1°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        -4.3°                                        benzoate (c = 1, CHCl.sub.3)                                                                   (III-46) (c = 1, CHCl.sub.3)                                 (IX-46)  n.sub.D.sup.20 1.4900                                                                          n.sub.D.sup.20 1.5030            47   2S-methyl-                                                                           5.86 g Methyl 4-(2S-                                                                          3.10 g  4-(2S-methyl-                                                                          1.08 g                                propyl (0.025 mole)                                                                         methoxypropoxy-                                                                        (yield 65%)                                                                           propoxymethyl)-                                                                        (yield 96%)                           tosylate      methyl)benzoate                                                                        [α].sub.D.sup.20 +6.8°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        +7.1°                                        (IX-47)  (c = 1, CHCl.sub.3)                                                                   (III-47) (c = 1, CHCl.sub.3)                                          n.sub.D.sup.20 1.4960                                                                          m.p. 64-66° C.            48   2S-propoxy-                                                                          6.54 g Methyl 4-(2S-                                                                          3.30 g  4-(2S-propoxy-                                                                         1.22 g                                propyl (0.024 mole)                                                                         propoxypropoxy-                                                                        (yield 62%)                                                                           propoxymethyl)-                                                                        (yield 97%)                           tosylate      methyl)benzoate                                                                        [α].sub.D.sup.20 +6.5°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        +6.8°                                        (IX-48)  (c = 1, CHCl.sub.3)                                                                   (III-48) (c = 1, CHCl.sub.3)                                          n.sub.D.sup.20 1.4944                                                                          m.p. 57-59° C.            49   2S-octyl-                                                                            8.22 g Methyl 4-(2S-                                                                          3.57 g  4-(2S-octyloxy-                                                                        1.53 g                                oxypropyl                                                                            (0.024 mole)                                                                         octyloxypropoxy-                                                                       (yield 53%)                                                                           propoxymethyl)-                                                                        (yield 95%)                           tosylate      methyl)benzoate                                                                        [α].sub.D.sup.20 +4.3°                                                   benzoic acid                                                                           [α].sub.D.sup.20                                                        +4.9°                                        (IX-49)  (c = 1, CHCl.sub.3)                                                                   (III-49) (c = 1, CHCl.sub.3)                                          n.sub.D.sup.20 1.4907                                                                          n.sub.D.sup.20                   __________________________________________________________________________                                                 1.5024                       

Preparation Examples 50 and 51 (starting material)

Reaction, post-treatment and purification were carried out similarly toin the Preparation Example 40 (starting material) except that opticallyactive alcohols shown in Table-VII were used in place of 2S-butanol toobtain the results shown in Table-VII.

                                      TABLE (VII)                                 __________________________________________________________________________    Prepa-           Optically active Optically active                            ration                                                                             Optically active                                                                          benzoate (IX)    (III)                                       Example                                                                            alcohols (XII)       Yield and       Yield and                           (starting  Amount         Physical        Physical                            material)                                                                          Name  used  Name     properties                                                                            Name    property                            __________________________________________________________________________    50   2R-octanol                                                                          5.21 g                                                                              Methyl 4-(2R-                                                                          3.56 g  4-(2R-octyloxy-                                                                       1.28 g                                         (0.04 mole)                                                                         octyloxymethyl)-                                                                       (yield 64%)                                                                           methyl)benzoic                                                                        (yield 96%)                                          benzoate [α].sub.D.sup.20 -6.9°                                                   acid    [α].sub.D.sup.20                                                        -5.5°                                         (IX-50)  (c = 1, CHCl.sub.3)                                                                   (III-50)                                                                              (c = 1, CHCl.sub.3)                                           n.sub.D.sup.20 1.4971                                                                         m.p. 41˜43° C.         51   2R-decanol                                                                          6.33 g                                                                              Methyl 4-(2R-                                                                          3.55 g  4-(2R-decyloxy-                                                                       1.40 g                                         (0.04 mole)                                                                         decyloxymethyl)-                                                                       (yield 58%)                                                                           methyl)benzoic                                                                        (yield 95.5%)                                        benzoate [α].sub.D.sup.20 -4.1°                                                   acid    [α].sub.D.sup.20                                                        -3.9°                                         (IX-51)  (c = 1, CHCl.sub.3)                                                                   (III-51)                                                                              (c = 1, CHCl.sub.3)                                           n.sub.D.sup.20 1.4946                                                                         waxy solid                          __________________________________________________________________________     Optical rotation was each measured under conditions of (c = 1,                CHCl.sub.3).                                                             

Preparation Example 52 (starting material)

Into a four-necked flask equipped with a stirrer and thermometer, 2.96 g(0.04 mole) of 2S-butanol and 15 ml of dimethylformamide were added,followed by cooling to 5° C. or lower. 0.48 g (0.02 mole) of sodiumhydride was added, followed by stirring at the same temperature for 1hour and further at 20° to 25° C. for 2 hours. Subsequently, 6.64 g(0.02 mole) of 3-(4-acetylphenyl)propyl tosylate were added thereto at20° to 25° C. over 1 hour, followed by stirring at the same temperaturefor 2 hours and further at 30° to 35° C. for 2 hours. After completionof the reaction, the reaction mixture was poured into ice-water andextracted with 50 ml of toluene, sine organic phase was washed withwater and then dried over anhydrous magnesium sulfate, followed bydistillation of the solvent. The concentrated residue was purified bycolumn chromatography with toluene to obtain 3.04 g (yield: 65%) of4-{3-(2S-butoxy)propyl}acetophenone (VI-52).

[α]_(D) ²⁰ =+7.5° (c=1, CHCl₃),

n_(D) ²⁰ =1.5123.

Preparation Example 53 (starting material)

5.21 g (0.04 mole) of 2R-octanol, 15 ml of N-methylpyrollidone and 3 mlof tetrahydrofuran were added, followed by cooling to 5° C. or lower.0.5 g (0.25 mole) of sodium hydride was added, followed by stirring atthe same temperature for 1 hour and further at 20° to 25° C. for 2hours. Subsequently, 6.64 q (0.02 mole) of 3-(4-acetylphenyl)propyltosylate were added thereto at 20° C. or lower over 1 hour, followed bystirring at the same temperature for 2 hours and further at 30° to 35°C. for 2 hours. After completion of the reaction, the reaction mixturewas poured into ice and extracted with 50 ml of toluene. Subsequently,purification was carried out similarly to in the Preparation Example 52(starting material) to obtain 3.48 g (yield: 60%) of4{3-(2R-octyloxy)propyl}acetophenone (VI-53).

[α]_(D) ²⁰ =+4.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5027.

Preparation Examples 54 to 59 (starting material)

Reaction, post treatment and purification were carriedout similarly toin the Preparation Example 52 (starting-material) except that opticallyactive alcohols (XII) as shown in Table-VIII were used in place of2S-butanol to obtain the results as shown in Table-VIII.

                                      TABLE (VIII)                                __________________________________________________________________________    Prepa-                                                                        ration                                                                             Optically active                                                                            Optically active                                           Example                                                                            alcohols (XII)                                                                              acetophenone (VI)                                          (starting   Amount              Physical                                      material)                                                                          Name   used   Name     Yield                                                                             property                                      __________________________________________________________________________    54   2S-methyl-                                                                           3.52 g 4-{3-(2S-                                                                              3.67 g                                                                            [α].sub.D.sup.20 +3.1°                butanol                                                                              (0.04 mole)                                                                          methylbutoxy)-                                                                         (74%)                                                                             n.sub.D.sup.20 1.5048                                            propyl}aceto-                                                                 phenone (VI-54)                                            55   4S-methyl-                                                                           2.91 g 4-{3-(4S-                                                                              4.31 g                                                                            [α].sub.D.sup.20 +1°                  hexanol                                                                              (0.025 mole)                                                                         hexyloxy)-                                                                             (78%)                                                                             n.sub.D.sup.20 1.4997                                            propyl}aceto-                                                                 phenone (VI-55)                                            56   2S-fluoro-                                                                           5.37 g 4-{3-(2S-                                                                              2.06 g                                                                            [α].sub.D.sup.20 -6.4°                heptyl (0.04 mole)                                                                          fluoroheptyloxy)-                                                                      (35%)                                                                             n.sub.D.sup.20 1.5004                              alcohol       propyl}aceto-                                                                 phenone (VI-56)                                            57   2S-methyl-                                                                           2.70 g 4-{3-(2S-                                                                              3.75 g                                                                            [α].sub.D.sup.20 +6.2°                propanol                                                                             (0.03 mole)                                                                          methylpropoxy)-                                                                        (72%)                                                                             n.sub.D.sup.20 1.5108                                            propyl}aceto-                                                                 phenone (VI-57)                                            58   4S-methyl-                                                                           3.54 g 4-{3-(4S-                                                                              4.34 g                                                                            [α].sub.D.sup.20 +4.6°                propanol                                                                             (0.03 mole)                                                                          propoxypropoxy)-                                                                       (78%)                                                                             n.sub.D.sup.20 1.4999                                            propyl}aceto-                                                                 phenone (VI-58)                                            59   2S-octyl-                                                                            5.65 g 4-{3-(2S-                                                                              4.39 g                                                                            [α].sub.D.sup.20 +4.0°                oxypropanol                                                                          (0.03 mole)                                                                          octyloxypropoxy)-                                                                      (63%)                                                                             n.sub.D.sup.20 1.4973                                            propyl}aceto-                                                                 phenone (VI-59)                                            __________________________________________________________________________     Optical rotation was each measured under conditions of (c = 1,                CHCl.sub.3).                                                             

Preparation Example 60 (starting material)

Into an apparatus similar to in Preparation Example 52 (startingmaterial) were added 4.4 g (0.05 mole) of 2S-methylbutanol and 20 ml ofdimethylformamide, and 0.48 g (0.02 mole) of sodium hydride was added at5° C. or lower, followed by stirring at the same temperature for 1 hourand further at 20° to 25° C. for 2 hours. Subsequently, 4.82 g (0.02mole) of 3-(4-acetylphenyl)propyl bromide were added thereto at 15° to20° C., followed by maintaining the temperature at the same temperaturefor 2 hours and further at 35° to 45° C. for 1 hour. After completion ofthe reaction, the reaction mixture was poured into ice and extractedwith 50 ml of toluene. Subsequently, purification was carried outsimilarly to in the Preparation Example 52 (starting-material) to obtain1.84 g (yield: 37%) of 4-{ 3-(2S-methylbutoxy)propyl}acetophenone(VI-60).

Preparation Example 61 (starting material)

3.52 g (0.04 mole) of 2S-methylbutanol and 15 ml of dimethylformamidewere added, and 0.48 g (0.02 mole) of sodium hydride was added theretoat 5° C. or lower, followed by maintaining the temperature at the sametemperature for 1 hour and further at 20° to 25° C. for 2 hours.Subsequently, 6.36 g (0.02 mole) of 2-(4-acetylphenyl)ethyl tosylatewere added thereto at 20° C. or lower, followed by stirring at the sametemperature for 1 hour and further at 20° to 30° C. for 1 hour.

After completion of the reaction, post-treatment and purification werecarried out similarly to in the Preparation Example 52 (startingmaterial) to obtain 1.36 g (yield: 29%) of4-{2-(2S-methylbutoxy)ethyl}acetophenone (VI-61).

[α]_(D) ²⁰ =+4.6° (c=1, CHCl₃),

n_(D) ²⁰ =1.5115.

Preparation Example 62 (starting material)

Reaction, post-treatment and purification were carried out similarly toin the Preparation Example 61 (starting material) except that 5.21 g(0.04 mole) of 2R-octanol were used in place of 2S-methylbutanol toobtain 1.33 g (yield: 24%) of 4-{2-(2R-octyloxy)ethyl}acetophenone(VI-62).

[α]_(D) ²⁰ =-6.3° (c=1, CHCl₃),

n_(D) ²⁰ =1.5051.

Preparation Example 63 (starting material)

Reaction, post-treatment and purification were carried out similarly toin the Preparation Example 61 (starting material) except that 3.54 g(0.03 mole) of 2S-propoxypropanol were used in place of 2S-methylbutanolto obtain 3.86 g (yield: 73%) of4-{2-(2S-propoxypropoxy)ethyl}acetophenone (VI-63).

[α]_(D) ²⁰ =+4.8° (c=1, CHCl₃),

n_(D) ²⁰ =1.5003.

Preparation Example 64 (starting material)

Reaction, post treatment and purification were carried out similarly toin the Preparation Example 52 (starting material) except that 6.93 g(0.02 mole) of 4-(4-acetylphenyl)butyl tosylate were used in place of3-(4-acetylphenyl)propyl tosylate to obtain 3.13 g (yield: 63%) of4-{4-(2S-butoxy)butyl]-acetophenone (VI-64).

[α]_(D) ²⁰ =+9.1° (c=1, CHCl₃),

n_(D) ²⁰ =1.5030.

Preparation Example 65 to 68 (starting material)

Reaction, post treatment and purification were carried out similarly toin the Preparation Example 60 (starting material) except that opticallyactive alcohols (XII) as shown in Table (IX) were used in place of2S-butanol to obtain the results as shown in Table (IX).

                                      TABLE (IX)                                  __________________________________________________________________________    Prepa-                                                                        ration                                                                             Optically active                                                                           Optically active                                            Example                                                                            alcohols (XII)                                                                             acetophenone (VI)                                           (starting   Amount              Physical                                      material)                                                                          Name   used  Name      Yield                                                                             property                                      __________________________________________________________________________    65   2S-methyl-                                                                           3.52 g                                                                              4-{4-(2S- 3.57 g                                                                            [α].sub.D.sup.20 +1.5°                butanol                                                                              (0.04 mole)                                                                         methylbutoxy)-                                                                          (68%)                                                                             n.sub.D.sup.20 1.5016                                           butyl}aceto-                                                                  phenone (VI-65)                                             66   2R-octanol                                                                           5.21 g                                                                              4-{4-(2R- 3.71 g                                                                            [α].sub.D.sup.20 -2.4°                       (0.04 mole)                                                                         octyloxy)-                                                                              (61%)                                                                             n.sub.D.sup.20 1.4992                                           butyl}aceto-                                                                  phenone (VI-66)                                             67   2S-methyl-                                                                           5.16 g                                                                              4-{4-(2S- 3.88 g                                                                            [α].sub.D.sup.20 +3.6°                decanol                                                                              (0.03 mole)                                                                         methylundecyloxy)-                                                                      (56%)                                                                             n.sub.D.sup.20 1.4816                                           butyl}aceto-                                                                  phenone (VI-67)                                             68   2S-propoxy-                                                                          3.54 g                                                                              4-{4-(2S- 4.04 g                                                                            [α].sub.D.sup.20 +4.2°                propanol                                                                             (0.03 mole)                                                                         propoxy)butyl}-                                                                         (69%)                                                                             n.sub.D.sup.20 1.4990                                           acetophenone                                                                  (VI-68)                                                     __________________________________________________________________________     Optical rotation was each measured under conditions of (c = 1,                CHCl.sub.3).                                                             

Reference Example

Into a four-necked flask equipped with a stirrer and a thermometer, 84.0g (0.63 mole) of aluminum chloride and 450 ml of dichloromethane werecharged, followed by adding 51.8 g (0.66 mole) of acetyl chloride wereadded at 10° to 15° C. over 2 hours. After maintained at the sametemperature for 1 hour, 53.4 g (0.3 mole) of 3-phenylpropyl acetate wereadded thereto at 10° to 20° C. over 3 hours. After maintained at 25° C.for 4 hours, the reaction mixture was poured into ice-water, followed byaddition of 100 ml of dichloromethane to separate the organic phase. Theorganic phase was washed subsequently with water, 3% aqueous sodiumcarbonate solution and water. The organic phase was dried over magnesiumsulfate and then concentrated under reduced pressure to obtain 62.4 g(yield: 94.5%) of 4-(3-acetoxypropyl)acetophenone.

55.0 g (0.25 mole) of the 4-(3-acetoxypropyl)acetophenone obtainedabove, 65 g of 10% potassium hydroxide, 20 ml of tetrahybofuran and 60ml of methanol were charged, followed by stirring at room temperaturefor 5 hours. After completion of the reaction, the reaction mixture wasconcentrated under reduced pressure to distill the tetrahydrofuran andmethanol off. The residue was extracted with toluene. The organic phasewas further washed with water and then concentrated under reducedpressure to obtain 43.9 g (yield: 98.5%) of4-(3-hydroxypropyl)acetophenone.

Next, (a) to a mixture of 17.8 g (0.01 mole) of the4-(3-hydroxypropyl)acetophenone obtained above and 50 ml of pyridined,were added 21.7 g (0.105 mole) of toluenesulfonyl chloride at 10° C. orlower over 2 hours. After maintained at the same temperature for 2hours, the reaction mixture was poured into ice-water, adjusted to weakacidic with 20% aqueous hydrochloric acid solution and extracted with100 kl of toluene. The organic phase was washed with water, dried overmagnesium sulfate and concentrated under reduce pressure to obtain 32.7g (yield: 98.5%) of 3-(4-acetylphenyl)propyl tosylate.

Further, (b) 17.8 g (0.1 mole) of the 4-(3-hydroxypropyl)acetophenoneobtained above were dissolved in 7.91 g of pyridine and 70 ml oftoluene, and then 2.71 g (0.01 mole) of phosphorus tribromide were addedthereto at 0° to 10° C. After maintained at the same temperature for 3hours, the reaction mixture was poured into ice-water. Subsequently,washing with water, 2% aqueous sodium hydrogen carbonate solution andwater was carried out, and after the organic phase was dried overmagnesium sulfate, the solvent was distilled off to obtain 21.7 g(yield: 90%) of 3-(4-acetylphenyl)propyl bromide.

Next, 4-phenylbutyl acetate and 2-phenylethyl acetate were used,respectively, in place of 3-phenylpropyl acetate, followed by treatmentaccording to the methods of (a) and (b) to obtain the followingcompounds:

4-(4-acetylphenyl)butyl tosylate, 4-(4-acetylphenyl)butyl bromide,2-(4-acetylphenyl)ethyl tosylate and 2-(4-acetylphenyl)ethyl bromide.

EXAMPLE 1

Into a four-necked flask equipped with a stirrer and a thermometer werecharged 1.04 9 (5 millimole) of(+)-4-[2-{2(S)-methylbutoxy}ethyl]phenol, 1.67 g (6 millimole) of4-decyloxybenzoic acid and 30 ml of anhydrous dichloromethane, and 1.22g (6 millimole) of N,N'-dicyclohexylcarbodiimide and 0.1 g of4-pyrrolidinopyridine were added thereto, followed by stirring at roomtemperature for one day.

After completion of the reaction, precipitates formed were filtered offand diluted with 200 ml of toluene. The organic phase was washed withwater, 5% aqueous acetic acid solution, 5% aqueous sodium hydrogencarbonate solution and water in this order and then dried over anhydrousmagnesium sulfate, followed by concentration under reduced pressure. Theobtained residue was purified by silica gel column chromatography(eluent: toluene-ethyl acetate) to obtain 2.10 g (yield: 90%) of(+)-4-[2-{2(S)-methylbutoxy}ethyl]phenyl 4-decyloxybenzoate.

EXAMPLE 2

Into a four-necked flask equipped with a stirrer and a thermometer werecharged 1.14 g (5 millimole) of (+)-4-[2-{2(S)-octyloxy}ethyl]phenol and20 ml of pyridine, and 1.78 g (6 millimole) of 4-decyloxybenzoicchloride were added thereto at 20° to 25° C., followed by stirring atthe same temperature and thereafter at 40° C. for 4 hours.

After completion of the reaction, the reaction mixture was poured into4N hydrochloric acid, followed by extraction with 200 ml of toluene. Theorganic phase was washed with water, 5% aqueous sodium hydrogencarbonate solution and water in this order and then dried over anhydrousmagnesium sulfate, followed by concentration under reduced pressure. Theobtained residue was purified by silica gel column chromatography(eluent: toluene-etypl acetate) to obtain 2.33 g (yield: 95.5%) of(+)-4-{2-[2S-octyloxy}ethyl]phenyl 4-decyloxybenzoate.

EXAMPLE 3

Into a four-necked flask were charged 1.18 g (5 millimole) of(+)-4-[2-{2(S)-methylbutoxy}ethyl]benzoic acid, 1.50 g (6 millimole) of4-decyloxyphenol and 30 ml of dichlorometahne, and 1.13 g (5.5millimole) of N,N'-dicyclohexylcarbodiimide and 0.1 g of4-pyrrolidinopyridine were added thereto, followed by stirring at 25° to30° C. for 24 hours. After completion of the reaction, precipitates werefiltered off and subsequently, post-treatment and purification werecarried out similarly to in Example 1 to obtain 2.08 g (yield: 89%) of(+)-4decyloxyphenyl 4-[2-{2S-methylbutoxy}ethyl]benzoate.

EXAMPLE 4

Reaction, post-treatment and purification were carried out similarly toin Example 3 except that 1.11 g (5 millimole) of(+)-4-[{2(S)-methylbutoxy}methyl]benzoic acid were used in place of(+)-4-[2-{2(S)-methylbutoxy}ethyl]benzoic acid to obtain 2.0 g (yield:88%) of (+)-4-decyloxyphenyl 4-[{2(S)-methylbutoxy}methyl]benzoate.

EXAMPLE 5

Into an apparatus similar to in Example 1, were charged 1.04 g (5millimole) of (+)-4-[2-{2(S)-methylbutoxy}ethyl]phenol, 2.12 g (6millimole) of 4'-decyloxy-4-biphenylcarboxylic acid and 40 ml ofdichloromethane, and then 1.22 g (6 millimole) ofN,N'-dicyclohexylcarbodiimide and 0.1 g of 4-pyrrolidinopyridine wereadded thereto, followed by stirring at room temperature for one day.

Subsequently, post-treatment and purification were carried out similarlyto in Example 1 to obtain 2.45 g (yield: 90%) of(+)-4-[2-{2(S)-methylbutoxy}ethyl]phenyl4'-decyloxy-4-biphenylcarboxylate.

EXAMPLES 6 TO 33

Reaction, post-treatment and purification were carried out similarly toin Example 1 or 3 except that a starting-material used is placed withthose shown in Table-1, to obtain the results shown in Table 1.

    TABLE 1      In the column of phase transition temperature S.sub.1 represents     smectic phase unidentified Ex- Optically active material Starting     material   [α].sub.D.sup.20 Angle Phase am- compound (III) or (V)     compound (II) or (IV) Optically active esters (I) Yield of rotation     transition ple R.sub.2 R'** n k R.sub.1 Y l m R'*** R.sub.1 Y X R.sub.2     l m n k (%) (c =      1, CHCl.sub.3) temperature (°C.)             1 2(S)-methyl-butyl  2 0 n-C.sub.10 H.sub.21 O 1 1 OH n-C.sub.10     H.sub.21 O COO 2(S)-methyl-butyl 1 1 2 0 90 +2.5°      ##STR24##        2 2(S)-octyl  " 0 n-C.sub.10 H.sub.21 " " " Cl " " " 2(S)-Octyl " " "     0 95.5 +2.8°   3 2(S) methyl-butyl OH " 0 " " " "  " " OCO     2(S)-methyl-butyl " " " 0 89 +2°      ##STR25##        4 2(S) methyl-butyl " 1 0 " " " "  " " " 2(S)-methyl-butyl " " 1 0 88     +2.9°      ##STR26##        5 2(S) methyl-  2 0 " " 2 " OH " " COO 2(S)-methyl- 2 " 2 0 90     +1.9°  butyl            butyl  6 2(S)butyl OH 1 0 n-C.sub.8     H.sub.17 COO 1 1  n-C.sub.8 H.sub.17 COO OCO 2(S)-butyl 1 1 1 0 87     -1.5°   7 2(S)methyl-butyl " 2 0 n-C.sub.10 H.sub.21 O 2 "     n-C.sub.10 H.sub.21 O " 2(S)-methyl-butyl 2 " 2 0   90.5 +2.8°      ##STR27##        8 2(S)methyl-  " 0 n-C.sub.9 H.sub.19 -- 1 0 OH n-C.sub.9 H.sub.19 -- C     OO 2(S)-methyl- 1 0 0 0 89 +2.2°  butyl            butyl  9     2(R)-butyl  2 0 n-C.sub.10 H.sub.21 O 1 1 OH n-C.sub.10 H.sub.21 O "     2(R)-butyl 1 1 2 0 88 +5.3° 10 2(S)-methyl-  2 0 n-C.sub.16     H.sub.33 " " " " n-C.sub.10      H.sub.21 " "2(S)-methyl- " " " 0 86 +1.5°  butyl     butyl 11 2(S)-butyl OH 1 0 n-C.sub.10 H.sub.21 OCO " "  n-C.sub.10     H.sub.21 OCO OCO 2(S)-butyl " " 1 0 90 12 2(S)-butyl OH 1 0 n-C.sub.10     H.sub.21 O 2 1  n-C.sub.10      H.sub.21 O OCO 2(S)-butyl 2 1 1 0 88 +4°    13 4(S)-methyl-hexyl     " "0 " " 1 "  " " " 4(S)-methyl-hexyl 1 " " 0 88      ##STR28##       14 2(S)methyl-  2 0 n-C.sub.6 H.sub.13 " 2 " OH n-C.sub.6 H.sub.13 "     COO 2(S)-methyl- 2 " 2 0 87 +3.1°  butyl            butyl 15     2(S)-Fluoro-  " 0 n-C.sub.10 H.sub.21 " 1 " " n-C.sub.10 H.sub.21 " "     2(S)-fluoro- 1 " " 0 89  heptyl            keptyl  16 4(S)-methyl-hexyl     OH 1 0 " " " "  " " OCO 4(S)-methyl-hexyl " " 1 0 85 +1°      ##STR29##       17 2(S)-butyl OH 1 0 n-C.sub.10 H.sub.21 O " "  n-C.sub.10 H.sub.21 O  O     CO 2(5)-butyl 1 1 1 0 90 -1.3°      ##STR30##       18 2(S)-butyl OH 1 0 n-C.sub.8 H.sub.17 O 2 1  n-C.sub.8 H.sub.17 O     OCO 2(S)-butyl 2 1 1 0 88 +4.4°      ##STR31##       19 4(S)-methylhexyl " 1 0 n-C.sub.10 H.sub.21 O 2 1  n-C.sub.10     H.sub.21 O OCO 4(S)-methylhexyl 2 1 1 0 86 +1.2°      ##STR32##       20 2(S)-pro-poxypropyl  1 0 n-C.sub.10 H.sub.21 O 1 1 OH n-C.sub.10     H.sub.21 O COO 2(S)-pro-poxypropyl 1 1 1 0 91 +4.1°      ##STR33##       21 2(S)-pro-poxypropyl  2 0 n-C.sub.8 H.sub.17 O 1 1 OH n-C.sub.8     H.sub.17 O COO 2(S)-pro-poxypropyl 1 1 2 0 90 +3.7°      ##STR34##       22 2(S)-pro-poxypropyl  2 0 n-C.sub.8 H.sub.17 -- 1 0 OH n-C.sub.8     H.sub.17 -- COO 2(S)-pro-poxypropyl 1 1 2 0 90 +3.9°      ##STR35##       23 2(S)-pro-poxypropyl OH 2 0 n-C.sub.8 H.sub.17 O 1 1  n-C.sub.8     H.sub.17 O OCO 2(S)-pro-poxypropyl 1 1 2 0 87 +3.8°      ##STR36##       24 2(S)-pro-  2 0 n-C.sub.10 H.sub.21 O 2 1  n-C.sub.10 H.sub.21 O COO     2(S)-pro- 2 1 2 0 88 +2.7°  poxypropyl            poxypropyl 25     2(S)-butyl  1 1 n-C.sub.10 H.sub.21 O 1 1 OH n-C.sub.10 H.sub.21 O COO     2(S)-butyl 1 1 1 1 90 -3.2°  26 2(S)-butyl OH 2 1 n-C.sub.10     H.sub.21 O 1 1  n-C.sub.10      H.sub.21 O OCO 2(S)-butyl 1 1 2 1 85 -3.4°      ##STR37##       27 1(S)-chloro-2(S)methyl-butyl  1 1 n-C.sub.10 H.sub.21 O 1 1 OH     n-C.sub.10 H.sub.21 O COO 1(S)-chloro-2(S)-methyl-butyl 1 1 1 1 89     -6.7°      ##STR38##       28 1(S)-chloro-2(S)methyl-butyl  2 1 n-C.sub.8 H.sub.17 O 1 1 OH     n-C.sub.8 H.sub.17 O COO 1(S)-chloro-2(S)-methyl-butyl 1 1 2 1 87     -6.2°      ##STR39##       29 1(S)-chloro-2(S)methyl- butyl OH 1 1 n-C.sub.10 H.sub.21 O 1 1     n-C.sub.10 H.sub.21 O OCO 1(S)-chloro-2(S)-methyl-butyl 1 1 2 1 84     -5.9°      ##STR40##       30 1(S)-pro-poxyethyl  2 1 n-C.sub.10 H.sub.21 O 1 1 OH n-C.sub.10     H.sub.21 O COO 1(S)-pro-poxyethyl 1 1 2 1 88 +2.9°      ##STR41##       31 1(S)-pro-poxyethyl OH 2 1 n-C.sub.10 H.sub.21 O 1 1  n-C.sub.10     H.sub.21 O OCO 1(S)-pro-poxyethyl 1 1 2 1 90 +3.1°      ##STR42##       32 1(S)-pro-poxyethyl  1 1 n-C.sub.10 H.sub.21 -- 1 0 OH n-C.sub.10     H.sub.21 -- COO 1(S)-pro-poxyethyl 1 0 1 1 92 +3.2°      ##STR43##        33 1(S)-pro-  2 1 n-C.sub.8 H.sub.17 O 2 1 OH n-C.sub.8 H.sub.17 O     COO 1(S)-pro- 2 1 2 1 85 +1.8°  poxyethyl   poxyethyl     **In the column R', /OH represents optically active carboxylic acid     compounds (III), and / represents optically active phenols (V).    Cl represents carboxylic acid compounds (IV).

As shown in the Examples described above, the compounds of the presentinvention in which l=2 have a comparatively broad temperature range forthe Sc* phase, and by using said compounds as a formulation component ofa liquid crystal composition, it is possible to extend the temperaturerange for the Sc* phase of the liquid crystal composition.

Further, viscosity coefficients of the representative compounds amongthe compounds obtained in the Examples described above are as shown inTable 1-b. The compounds of the present invention in which l=1 have asmall viscosity coefficient and is found to be useful as a component forenhansing the response speed of the liquid crystal composition.

                  TABLE 1                                                         ______________________________________                                        Example             Viscosity coefficient*                                    No.           l     (Pa · sec)                                       ______________________________________                                         1            1     0.32                                                       7            2     0.98                                                      16            1     0.40                                                      19            2     1.05                                                      ______________________________________                                         *Extrapolated value at 20° C.                                     

EXAMPLE 34

A liquid crystal composition was formulated from a known liquid crystalcompound (A) having the following phase transition temperature (° C.)and spontaneous polarization value and a liquid crystal compounddescribed in the Example 1: ##STR44##

The formulation of the liquid crystal composition was carried out byweighing a respective compound so as to give a formulation rate of 80mole % of the known liquid crystal compound and 20 mole % for the liquidcrystal compound described in the Example 1 and by melting the resultingmixture by heating in a sample bottle. The phase transition temperatureand voluntary polarization value at 20° C. of the thus obtained liquidcrystal composition are shown below. ##STR45##

The liquid crystal composition described above exhibits Sc* phase in alower temperature range than in the known liquid crystal compound (A)and has a broader temperature range of Sc* phase (i.e., a differencebetween a temperature at which transited from Sc* phase to S_(A) phaseand a temperature at which transited from S_(B) phase to Sc* phase) andmoreover has an increased spontaneous polarization value.

[Preparation Method for Liquid Crystal Element]

On a glass substrate provided with an indium oxide transparent electrodewas provided a polyimide type polymer coating film, followed byeffecting of rubbing treatment toward a predetermined direction. Aliquid crystal cell was assembled by employing glass fibers (diameter: 6μm) as a spacer so as to maintain the rubbing directions of two piecesof the glass paralleled, and the liquid crystal composition describedabove was charged thereinto and sealed under vacuum to obtain a liquidcrystal element.

The liquid crystal element was combined with a polarizer. When 20 V wasapplied in electrolysis, change in intensity of transmitted light wasobserved. The response speed obtained from the change in intensity oftransmitted light was found to be 110 μsec at 20° C.

Thus, it has been confirmed that a liquid crystal composition having Sc*phase in a lower temperature range and excellent in high speed responsecan be obtained by adding the liquid crystal compounds of the presentinvention.

EXAMPLE 35

Into a four-necked flask equipped with a stirrer and a thermometer werecharged 1.11 g (5 millimole) of(+)-4-[3-{2(S)-methylbutoxy}propyl]phenol, 1.67 g (6 millimole) of4-decyloxybenzoic acid and 30 ml of anhydrous dichlomethane, and then1.22 g (6 millimole) of N,N'-dicyclohexylcarbodiimide and 0.1 g of4-pyrrolidinopyridine were added thereto, followed by stirring at roomtemperature for one day. After completion of the reaction, precipitatesformed were filtered off and diluted with 200 ml of toluene. The organicphase was washed with water, 5% aqueous acetic acid solution, water, 5%aqueus sodium hydrogen carbonate solution and water in this order andthen dried over anhydrous magnesium sulfate, followed by concentrationunder reduced pressure. The obtained residue was purified by silica gelcolumn chromttography (eluent: toluene-ethyl acetate) to obtain 2.18 g(yield: 90.4%) of (+)-4-[3-{2(S)-methylbutoxy}propyl]phenyl4-decyloxybenzoate.

EXAMPLE 36

Into a four-necked flask equipped with a stirrer and a thermometer werecharged 1.18 g (5 millimole) of (+)-4-[4-{2(S)-methylbutoxy}butyl]phenoland 20 ml of pyridine, and then 1.7 g (6 millimole) of 4-octyloxybenzoicchloride were added thereto at 20° to 25° C., followed by stirring atthe same temperature and thereafter at 40° C. for 4 hours.

After completion of the reaction, the reaction mixture was poured into4N hydrochloric acid, followed by extraction with 200 ml of toluene. Theorganic phase was washed with water, 5% aqueous sodium hydrogencarbonate solution and water in this order and then dried over anhydrousmagnesium sulfate, followed by concentration under reduced pressure. Theobtained residue was purified by silica gel column chromatography(eluent: toluene-ethyl acetate) to obtain 2.28 g (yield: 95%) of(+)-4-[4-;2S-methylbutoxy)butyl]phenyl 4-octyloxybenzoate.

EXAMPLE 37

Into an apparatus similar to in Example 1 were charged 1.04 g (5millimole) of (+)-4-[3-(2(S)-butoxy)propyl]phenol, 1.95 g (6 millimole)of 4'-octyloxy-4-biphenylcarboxylic acid and 40 ml of chloroform, andinto this mixture 1.22 g (6 millimole) of N,N'-dicyclohexylcarbodiimideand 0.1 g of 4-pyrrolidino- pyridine were added, followed by stirring atroom temperature for one day.

Subsequently, post-treatment and purification were carried similarly toin Example 1 to obtain 2.30 g (yield: 89%) of(+)-4-[3-(2S-butoxy)propyl]phenyl 4'-octyloxy-biphenylcarboxylate.

EXAMPLE 38

Into a four-necked flask were charged 1.25 g (5 millimole) of(+)-4-[3-{2(S)-methylbutoxy}propyl]benzoic acid, 1.50 g (6 millimole) of4-decyloxyphenol, 25 ml of anhydrous dichloromethane and 5 ml oftetrahydrofuran, and then 1.13 g (5.5 millimole) ofN,N'-dicyclohexylcarbodiimide and 0.05 g of 4-pyrrolidinopyridine wereadded thereto, followed by stirring at 25° to 35° C. for 20 hours.

After completion of the reaction, precipitates were filtered off andsubsequently post-treatment and purification were carried out similarlyto in Example 1 to obtain 2.19 g (yield: 91%) of (+)-4-decyloxyphenyl4-[3-(2(S)-methylbutoxy)propyl]benzoate.

EXAMPLE 39

Into a four-necked flask were charged 1.18 g of(+)-4-[3-(2(S)-butoxy)propyl]benzoic acid, 1.96 g (6 millimole) of4'-decyloxy-4-biphenol and 40 ml of anhydrous dichloromethane, and then1.13 g (5.5 milimole) of N,N'-dicyclohexylcarbodiimide and 0.1 g ofpyridine were added thereto, followed by stirring at 30° to 35° C. for20 hours. Subsequently, post-treatment and purification were carried outsimilarly to in Example 1 to obtain 2.39 g (yield: 88%) of(+)-4'-decyloxybiphenylyl 4-[3-(2(S)-butoxy)-propyl]benzoate.

EXAMPLES 40 TO 86

Reaction and post-treatment were carried out similarly to in Example 35or 38 except that the starting material compounds used were placed withthose as shown in Table 2, to obtain results as shown in Table 2.

    TABLE 2      Starting-material Optically active    Phase compound starting-material     Optically active  [α].sub.D.sup.20 Angle transition (II) or (IV)     compound (III) or (V) ester derivative (I) Yield of rotation temperature E     xample R.sub.1 Y l n k R.sub.2 R.sub.1 Y l X n k R.sub.2 (%) (c = 1,     CHCl.sub.3) (°C.)                        35 n-C.sub.10 H.sub.21 O 1 3 0 2(S)-methyl-bytyl     n-C.sub.10 H.sub.21 O 1 COO 3 0 2(S)-methyl-bytyl 95 +2°      ##STR46##       36 n-C.sub.8 H.sub.17 O 1 4 0 2(S)-methyl-bytyl n-C.sub.8 H.sub.17 O 1 C     OO 4 0 2(S)-methyl-bytyl 95 +1.1°      ##STR47##       37 n-C.sub.8 H.sub.17 O 2 3 0 2(S)-butyl n-C.sub.8 H.sub.17 O 2 COO 3     0 2(S)-butyl 89 +6.0°      ##STR48##       38 n-C.sub.10 H.sub.21 O 1 3 0 2(S)-methyl-butyl n-C.sub.10 H.sub.21 O     1 OCO 3 0 2(S)-methyl-butyl 91 +1.6°      ##STR49##       39 n-C.sub.10 H.sub.21 O 2 3 0 2(S)-butyl n-C.sub.10 H.sub.21 O 2 OCO     3 0 2(S)-butyl 88 +5.9°  40 n-C.sub.10      H.sub.21 O 1 4 0 2(S)-butyl n-C.sub.10 H.sub.21 O 1 COO 4 0 2(S)-butyl     90 +4.8°      ##STR50##       41 n-C.sub.8 H.sub.17 O 1 3 0 2(R)-octyl n-C.sub.8 H.sub.17 O 1 COO 3     0 2(R)-octyl 88.5 -2.4°      ##STR51##       42 n-C.sub.10 H.sub.21 O 2 3 0 2(S)-methyl-butyl n-C.sub.10 H.sub.21 O     2 COO 3 0 2(S)-methyl-bytyl 89 -1.5°      ##STR52##       43 n-C.sub.8 H.sub.17 O 1 3 0 4(S)methyl- n-C.sub.8 H.sub.17 O 1 COO 3     0 4(S)-methyl 90       hexyl       hexyl 44 n-C.sub.8 H.sub.17 O 1 3 0     2(R)-octyl n-C.sub.8 H.sub.17 O 1 OCO 3 0 2(R)-octyl 87 -2°   45     n-C.sub.10 H.sub.21 O 1 5 0 2(S)-butyl n-C.sub.10 H.sub.21 O 1 COO 5 0     2(S)-butyl 86 +2.5° 46 n-C.sub.9 H.sub.10 --* 2 4 0 2(S)-butyl     n-C.sub.9 H.sub.19 -- 2 COO 4 0 2(S)-butyl 88 +5.1°  47 n-C.sub.8     H.sub.17 COO 1 4 0 2(S)-butyl n-C.sub.8      H.sub.17 COO 1 COO 4 0 2(S)-butyl 86 +4.1°      ##STR53##       48 n-C.sub.8 H.sub.17 OCO 1 3 0 2(S)-butyl n-C.sub.8 H.sub.17 OCO 1     OCO 3 0 2(S)-butyl 90 +6.1° 49 n-C.sub.10 H.sub.21 O 1 3 0     2(S)-fluoro- n-C.sub.10 H.sub.21 O 1 COO 3 0 2(S)-fluoro- 89 -4°            heptyl       heptyl 50 n-C.sub.6 H.sub.18 O 2 3 0 2(S)-butyl     n-C.sub.6 H.sub.18 O 2 COO 3 0 2(S)-butyl 88 +6°   51 n-C.sub.16     H.sub.33 O 1 3 0 2(S)-methyl- n-C.sub.16      H.sub.33 O 1 COO 3 0 2(S)-methyl 86 +6°         butyl     butyl  52 n-C.sub.10 H.sub.21 O 1 3 0 2(S)-butyl n-C.sub.10 H.sub.21 O 1 C     OO 3 0 2(S)-butyl 92 +3.1°      ##STR54##       53 n-C.sub.8 H.sub.17 O 2 3 0 2(S)-butyl n-C.sub.8 H.sub.17 O 2 COO 3     0 2(S)-butyl 88 +5.8°      ##STR55##       54 n-C.sub.8 H.sub.17 O 2 3 0 2(R)-octyl n-C.sub.8 H.sub.17 O 2 OCO 3     0 2(R)-octyl 87 -3.8°      ##STR56##       55 n-C.sub.10 H.sub.21 O 1 3 0 2(S)-butyl n-C.sub.10 H.sub.21 O 1 OCO     3 0 2(S)-butyl 91 +5.2°      ##STR57##       56 n-C.sub.8 H.sub.17 O  1 3 0 2(R)-octyl n-C.sub.8 H.sub.17 O 1 OCO 3     0 2(R)-octyl 93 -1.7°      ##STR58##       57 n-C.sub.10 H.sub.21 O 1 4 -- 2(S)-methyl-butyl n-C.sub.10 H.sub.21     O 1 OCO 4 0 2(S)-methyl-butyl 90 +2.0°      ##STR59##       58 n-C.sub.8 H.sub.17 O 1 3 0 2(S)-butyl n-C.sub.8 H.sub.17 O 1 COO 3     0 2(S)-butyl 93 +3.9°      ##STR60##       59 n-C.sub.10 H.sub.21 --* 1 3 0 2(S)-butyl n-C.sub.10 H.sub.21 --* 1     COO 3 0 2(S)-butyl 94 +3.3°      ##STR61##       60 n-C.sub.7 H.sub. 15 O 1 3 0 2(S)-butyl n-C.sub.7 H.sub.15 O 1 COO 3     0 2(S)-butyl 92 +4.2°      ##STR62##       61 n-C.sub.9 H.sub.19 O 1 3 0 2(S)-butyl n-C.sub.9 H.sub.19 O 1 COO 3     0 2(S)-butyl 90 +3.5°      ##STR63##       62 n-C.sub.11 H.sub.23 O 1 3 0 2(S)-butyl n-C.sub.11 H.sub.23 O 1 COO     3 0 2(S)-butyl 92 +3.2°      ##STR64##       63 n-C.sub.12 H.sub.25 O 1 3 0 2(S)-butyl n-C.sub.12 H.sub.25 O 1 COO     3 0 2(S)-butyl 90 +2.8°      ##STR65##       64 n-C.sub.10 H.sub.21 O 1 3 0 2(R)-octyl n-C.sub.10 H.sub.21 O 1 COO     3 0 2(R)-octyl 88 -2.2°      ##STR66##       65 n-C.sub.8 H.sub.17 O 2 3 0 2(R)-octyl n-C.sub.8 H.sub.17 O 2 COO 3     0 2(R)-octyl 86 -4.1°      ##STR67##       66 n-C.sub.8 H.sub.17 O 1 4 0 2(R)-octyl n-C.sub.8 H.sub.17 O 1 OCO 4     0 2(R)-octyl 86 -1.6°      ##STR68##       67 n-C.sub.8 H.sub.17 O 2 4 0 2(R)-octyl n-C.sub. 8 H.sub.17 O 2 OCO 4     0 2(R)-octyl 84 -3.7°      ##STR69##       68 n-C.sub.8 H.sub.17 O 1 4 0 2(R)-octyl n-C.sub.8 H.sub.17 O 1 COO 4     0 2(R)-octyl 87 -2.5°      ##STR70##       69 n-C.sub.8 H.sub.17 O 2 4 0 2(R)-octyl n-C.sub.8 H.sub.17 O 2 COO 4     0 2(R)-octyl 86 -3.5°      ##STR71##       70 n-C.sub.10 H.sub.21 O 1 3 0 2(R)-fluoro-propyl n-C.sub.10 H.sub.21     O 1 COO 3 0 2(R)-fluoro-propyl 87 -0.7°      ##STR72##       71 n-C.sub.8 H.sub.17 O 1 3 0 2(S)-propoxy-propoxy n-C.sub.8 H.sub.17     O 1 COO 3 0 2(S)-propoxy-propyl 92 +3.2°      ##STR73##       72 n-C.sub.10 H.sub.21 O 1 3 0 2(S)-propoxy-propoxy n-C.sub.10     H.sub.21 O 1 COO 3 0 2(S)-propoxy-propyl 92 +3.0°      ##STR74##       73 n-C.sub.10 H.sub.21 O  1 4 0 2(S)-propoxy- n-C.sub.10 H.sub.21 O 1     COO 4 0 2(S)-propoxy- 89 +2.9°       propoxy       propyl 74     n-C.sub.10 H.sub.21 O 1 3 0 2(S)-propoxy- n-C.sub.10 H.sub.21 O 1 OCO 3     0 2(S)-propoxy- 90 +3.3°       propoxy       propyl 75 n-C.sub.10     H.sub.21 O 1 3 1 2(S)-butyl n-C.sub.10 H.sub.21 O 3 COO 3 1 2(S)-butyl     87 -2.6°      ##STR75##       76 n-C.sub.8 H.sub.17 O 2 3 1 2(S)-butyl n-C.sub.8 H.sub.17 O 2 COO 3     1 2(S)-butyl 85 -1.9°      ##STR76##       77 n-C.sub.10 H.sub.21 O 1 3 1 2(S)-butyl n-C.sub.10 H.sub.21 O 1 OCO     3 1 2(S)-butyl 86 -3.0°      ##STR77##       78 n-C.sub.8 H.sub.17 O 1 4 1 2(S)-butyl n-C.sub.8 H.sub.17 O 1 OCO 4     1 2(S)-butyl 85 -2.2°      ##STR78##       79 n-C.sub.8 H.sub.17 O 2 3 1 2(S)-butyl n-C.sub.8 H.sub.17 O 2 OCO 3     1 2(S)-butyl 83 -1.7°  80 n-C.sub.8      H.sub.17 O 1 3 1 1(S)-chloro-2(S)methyl-butyl n-C.sub.8 H.sub.17 O 1     COO 3 1 1(S)-chloro-2(S)-methyl-butyl 82 -5.3°      ##STR79##       81 n-C.sub.10      H.sub.21  O 1 3 1 1(S)-chloro-2(S)methyl-butyl n-C.sub.10 H.sub.21 O 1     COO 3 1 1(S)-chloro-2(S)-methyl-butyl 85 -4.2°      ##STR80##       82 n-C.sub.10 H.sub.21 O 1 4 1 1(S)-chloro-2(S)methyl-butyl n-C.sub.10     H.sub.21 O 1 COO 4 1 1(S)-chloro-2(S)-methyl-butyl 83 -3.9°      ##STR81##       83 n-C.sub.8 H.sub.17 O 2 3 1 1(S)-chloro- n-C.sub.8 H.sub.17 O 2 COO     3 1 1(S)-chloro- 81 -2.2°       2(S)methyl-       2(S)-methyl-        butyl       butyl  84 n-C.sub.10      H.sub.21 O 1 3 1 1(S)-chloro-2(S)methyl-butyl n-C.sub.10 H.sub.21 O 1     OCO 3 1 1(S)-chloro-2(S)-methyl-butyl 85 -4.6°      ##STR82##       85 n-C.sub.10 H.sub.21 O 1 3 1 1(S)-propoxy-ethyl n-C.sub.10 H.sub.21     O 1 COO 3 1 1(S)-propoxy-ethyl 88 +2.3°      ##STR83##       86 n-C.sub.10 H.sub.20 O 1 3 1 1(S)-propoxy-ethyl n-C.sub.10 H.sub.21     O 1 OCO 3 1 1(S)-propoxy-ethyl 89 +2.5°      ##STR84##

As shown in the Examples 35 to 86 described above, the compounds of thepresent invention in which l=2 have a comparatively wide temperatureran9e for the Sc* phase, and by using said compounds as a formulationcomponent of a liquid crystal composition, it is possible to extend thetemperature range for the Sc* phase.

Further, viscosity coefficients of the representative compounds amongthe compounds obtained in the Examples 35 to 86 described above are asshown in Table 2-b. As is apparent from this Table, the compounds of thepresent invention in which l=1 have a small viscosity coefficient and isfound to be useful as a component for enhancing the response speed ofthe liquid crystal.

                  TABLE 2                                                         ______________________________________                                        Example             Viscosity coefficient*                                    No.           l     (Pa · sec)                                       ______________________________________                                        24            1     0.39                                                      27            1     0.30                                                      29            1     0.47                                                      30            1     0.32                                                      31            2     0.95                                                      ______________________________________                                         *Extrapolated value at 20° C.                                     

EXAMPLES 87 AND 88

Liquid crystal compositions as shown in Table-3 were formulated byemploying the liquid crystal compounds in the Examples 55 and 63. Theformulation of the liquid crystal compositions were carried out byweighing a predetermined amount of predetermined compound and mixing thecompounds under heat-melting in a sample bottle. The phase transitiontemperature (° C.) and spontaneous polarization value at 20° C. of thethus obtained liquid crystal compositions are shown in Table-3.

[Preparation Method of Liquid Crystal Element]

On a glass substrate provided with an indium oxide transparent electrodewas provided a polyimide type polymer coating film, followed by rubbingtreatment in a predetermined direction. A liquid crystal cell wasassembled by employing glass fibers (diameter: 6 μm) as a spacer so asto maintain the rubbing directions of two pieces of the glassparalleled, and the liquid crystal composition described above wascharged thereinto and sealed under vacuum to obtain a liquid crystalelement.

This liquid crystal element was combined with a polarizer. When 20 V wasapplied in electrolysis, changes in intensity of transmitted light wasobserved. The response time was obtained from the changes in intensityof transmitted light at this time, the results of which are as shown inTable-3.

Thus, it has been confirmed that a liquid crystal composition having aphase transition temperature in a lower temperature range and excellentin high speed response can be obtained by adding the liquid crystalcompounds of the present invention.

                                      TABLE 3                                     __________________________________________________________________________                                         Phase transition                                                                            Spontaneous                                                                          Response            Exam-                                temperature   polarization                                                                         time                ple Composition (mole %)             (C.°)  (nC/cm.sup.2)                                                                        (μsec)           __________________________________________________________________________    Exam- ple 87                                                                       ##STR85##                                                                                                      ##STR86##    -44     80                      ##STR87##                                                                Exam- ple 88                                                                       ##STR88##                                                                                                      ##STR89##     -7    120                      ##STR90##                                                                __________________________________________________________________________     *Known compound (A)                                                           ##STR91##                                                                     spontaneous polarization -0 nC/cm.sup.2                                  

We claim:
 1. An optically active ester derivative represented by theformula (I): ##STR92## wherein R₁ represents an alkyl group having 3 to20 carbons toms; R₂ represents an optically active alkyl or alkoxyalkylgroup having 3 to 15 carbon atoms optionally substituted by halogenatoms; Y represents --O--, --COO-- or --OCO--; X represents --COO-- or--OCO--; l represents a number of 1 or 2; k and m each represent anumber of 0 to 1; and n represents a number of 1 to 6, provided thatwhen n=1, l =2 and when n=2, k=0.
 2. An optically active esterderivative according to claim 1, wherein X is --COO--.
 3. An opticallyactive ester derivative according to claim 1, wherein R₂ is an opticallyactive alkyl group having 3 to 15 carbon atoms.
 4. An optically activeester derivative according to claim 2, wherein l is
 1. 5. An opticallyactive ester derivative according to claim 2 or 4, wherein n is a numberof 2 to
 6. 6. A liquid crystal composition having at least twocomponents at least one of which is an optically active ester derivativerepresented by the formula (I): ##STR93## wherein R₁ represents an alkylgroup having 3 to 20 carbon atoms; R₂ represents an optically activealkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionallysubstituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; Xrepresents --COO-- or --OCO--; l represents a number of 1 or 2; k and meach represent a number of 0 or 1; and n represents a number of 1 to 6,provided that when n=1, l=2 and when n=2, k=0.
 7. The liquid crystalcomposition according to claim 6, wherein X in the formula (I)representing the optically active ester derivative is --COO--.
 8. Theliquid crystal composition according to claim 14, wherein l in theformula (I) representing the optically active ester derivative is
 1. 9.The liquid crystal composition according to claim 7 or 8, wherein n inthe formula (I) representing the optically active ester derivative is 3to
 6. 10. A light switching element employing a liquid crystalcomposition according to claim 6 as a liquid crystal material.
 11. Thelight switching element according to claim 10, wherein X in the formula(I) representing the optically active ester derivative is --COO--. 12.The light switching element according to claim 11, wherein l in theformula (I) representing the optically active ester derivative is
 1. 13.The light switching element according to claim 11 or 12, wherein n inthe formula (I) representing the optically active ester derivative is 3to 6.